Submersible pipe installation systems

ABSTRACT

In general, the present invention provides processes and apparatus for bending and straightening or otherwise installing marine pipelines at underwater installations, and includes systems in which marine pipelines are installed at water depths to 250 feet or more, utilizing an underwater chamber which may be operated with its interior wet, dry or combinations thereof. In one form, the system provides for interconnecting wellheads or other stations with manifolds or other stations and comprises running marine pipeline generally vertically downwardly from the water surface into the work chamber, mounted in operative association with an underwater wellhead or station, wherein the pipe is bent in the desired radius and through the desired angle and then straightened to exit from the chamber and wellhead in a substantially horizontal attitude such that it may then be pulled to a manifold or other underwater station with, for example, a wire line.

This is a division of application Ser. No. 733,377, filed Oct. 18, 1976,now U.S. Pat. No. 4,095,437.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to systems associated with thedrilling, completing and depleting of underwater wells, such as oil, gasor the like, and, more particularly, but not by way of limitation, tosystems for forming and installing pipes beneath the surface of a bodyof water.

2. Brief Description of the Prior Art

It has been the practice for a number of years to use drilling rigs inthe Gulf of Mexico and the oceans for the purpose of drilling andcompleting oil and gas wells and the like. Early offshore rigs wereadapted to rest on the floor or bottom of a body of water and drill in aso-called "sit on bottom" position. Thereafter, floating rigs weredeveloped which could drill while floating. While this permitted thedrilling of wells in water depths on the order of 1,000 feet or more itleft substantial problems such as how to convey fluid products to thesurface, for example.

For commercial reasons, when wells are drilled in deeper water, it isdesirable to provide an underwater oil or gas collecting station and toconvey the oil or gas from a number of wells to such collecting stationfrom whence it is conveyed to a surface collection station.

Moreover, it is not always commercially practical to use divers at suchdepths because of the limited time that they can remain at such depths,the cost of sophisticated support equipment required, as well as therelatively high salaries of the various personnel involved.

A major problem in perfecting such a deep water collecting system isthat of laying and installing the marine pipelines to interconnect thewells with the underwater collection station. Further, various problemsare encountered in making the terminal pipeline connections underwater,such as the problems associated with the alignment of the pipelines tobe connected, for example. U.S. Pat. No. 3,754,404 discloses a methodfor interconnecting offshore with other offshore, as well as onshore,installations utilizing a submersible chamber and a series of buoys andwire lines for stringing and pulling the flowline pipe to interconnectsuch stations.

U.S. Pat. No. 2,548,616 discloses a pipe straightener comprising aplurality of roller motor driven roller elements and a pipe bendercomprising a plurality of adjustable roller elements for use in passinga pipe string into a borehole and for use in withdrawing the pipe stringfrom the borehole.

U.S. Pat. No. 3,595,312 disclosed a method and apparatus for installingoffshore pipelines wherein the pipe was moved through a curved tube orJ-tube shaped to change the direction of the pipe from vertical tohorizontal, the pipe exiting the J-tube extending along the floor of abody of water. In one form, rollers were included in the J-tube forreducing friction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic, partial section, partial elevation viewshowing the pipe forming system of the present invention mounted in anoperating position on one form of a support structure.

FIG. 2 is a partial plan view of the pipe forming system of FIG. 1,showing the support structure of FIG. 1 in dashed-lines.

FIG. 3 is an elevational view of a portion of the pipe forming system ofFIG. 1, including a sectional view of a portion of the support structureof FIG. 1.

FIG. 4 is an enlarged elevational view of a typical first or secondforming assembly of the pipe forming system of FIG. 1.

FIG. 5 is an enlarged elevational view of a typical support frameportion of the first or second forming assembly shown in FIG. 4.

FIG. 6 is a partial elevational, partial sectional view of the supportframe portion of FIG. 5.

FIG. 7 is a diagrammatic view illustrating the installation of anelectrical cable or other flexible member through a pipe in accordancewith the present invention.

FIG. 8 is a diagrammatic view illustrating the installation of anelectrical cable and a utility fluid line at a support structure.

FIG. 9 is a fragmentary view illustrating one pipe installationconstructed in accordance with the present invention.

FIG. 10 is a fragmentary view illustrating another pipe installationarranged in accordance with the present invention.

FIG. 11 is a diagrammatic, partial sectional, partial elevational viewshowing a pipe forming system, similar to FIG. 1, but, mounted on amodified support structure.

FIG. 12 is a side elevational view of a pair of shaping rollerassemblies disposed near a forming assembly.

FIG. 13 is a plan view of the system shown in FIG. 13.

FIG. 14 is a diagrammatic end view of a portion of the system shown inFIGS. 12 and 13.

FIG. 15 is a diagrammatic, partial section, partial elevation viewshowing another embodiment of the pipe forming system of the presentinvention mounted in an operating position on one form of a supportstructure.

FIG. 16 is a diagrammatic, partial section, partial elevation viewshowing still another embodiment of the pipe forming system of thepresent invention mounted in an operating position on one form of asupport structure.

FIG. 17 is a diagrammatic view showing yet another embodiment of thepipe forming system of the present invention mounted on an offshoreplatform.

FIG. 18 is a side elevational view of the pipe forming system of FIG.17.

FIG. 19 is a plan view of the pipe forming system of FIGS. 17 and 18,the pipe forming system being shown in FIG. 19 in one operative positionin solid-lines and in one other operative position in dashed-lines.

FIG. 20 is a side elevational view of the pipe forming system of FIGS.17, 18 and 19.

FIG. 21 is a side elevational view of still another embodiment of thepipe forming system of the present invention.

FIG. 22 is a side elevational view of the pipe forming system of FIG. 21shown in a position for removing the pipe forming system from operativeengagement with the pipe.

FIG. 23 is a diagrammatic, partial sectional, partial elevational viewillustrating the installation of one pipe through another pipe inaccordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings in general and to FIGS. 1, 2 and 3 inparticular shown therein and designated via the general referencenumeral 10 is a pipe installation system which generally includes: asupport structure 12; a first forming assembly 14, which is movablyconnected to the support structure 12 and includes a portion forming apipe passageway 16; a second forming assembly 18, which is movablyconnected to the support structure 12 and includes a portion forming apipe passageway 20; and a riser 22, having a first end 24, a second end26 and an opening extending therethrough intersecting the ends 24 and 26and defining a pipe passageway 28, the riser 22 providing a fluid-tightpipe passageway 28 in a preferred embodiment. The riser 22 is connectedto the support structure 12 at a connection 30 and the second end 26 ofthe riser 22 is disposed generally near the pipe passageway 16 of thefirst forming assembly 14. The first and the second forming assemblies14 and 18 are positioned on the support structure 12 so that a pipe (apipe 32 being shown in the drawings, for example) is passable throughthe pipe passageways 16, 20 and 28 in a first direction 34 and in agenerally opposite, second direction 36 during the operation of the pipeinstallation system 10.

In general, the pipe installation system 10 is constructed to besubmersed in a body of water and connected to a base 38 at a connection40 (shown in FIG. 1), the base 38 being anchored or otherwise securedlysupported in the floor of the body of water (a body of water beingdiagrammatically illustrated in FIG. 1 with a surface 42 and a floor 44,having a floor surface 46, for example). The base 38 extends a distanceabove the floor surface 46. The pipe installation system 10 is connectedto the base 38 beneath the surface 42 of the body of water in oneassembled position of the pipe installation system 10 submersed in thebody of water. In this position, a portion of the riser 22, generallynear the first end 24 thereof, extends a distance generally above thesurface 42 of the body of water and the riser 22 extends a distancebelow the surface 42 into the body of water terminating with the secondend 26 of the riser 22, as illustrated in FIG. 1.

The pipe installation system 10 is constructed and utilized forinstalling pipe near the floor surface 46 from a vessel or otherstructure (not shown) located near the surface 42 of the body of water.During the operation, the pipe 32 is inserted through the first end 24,into the opening in the riser 22 and passed through the pipe passageway28 in the first direction 34. The pipe 32 is passed from the riser 22pipe passageway 28 into the pipe passageway 16 of the first formingassembly 14 and, as the pipe 32 is passed in the first direction 34through the pipe passageway 16, the pipe 32 is engaged by portions ofthe first forming assembly 14 for causing the portions of the pipe 32passing through the first forming assembly 14 to be formed inpredetermined radii. The pipe 32 is passed from the pipe passageway 16into the pipe passageway 20 of the second forming assembly 18 and, asthe pipe 32 is passed in the first direction 34 through the pipepassageway 20, the pipe 32 is engaged by portions of the second formingassembly 18 for causing the portions of the pipe 32 passing through thesecond forming assembly 18 to be formed in predetermined radii. Theforming assemblies 14 and 18 cooperate to form the pipe 32 throughpredetermined forming angles, and a particular forming angle isdetermined via the orientation of the forming assemblies 14 and 18relative to each other. The first and the second forming assemblies 14and 18 each are constructed so that the pipe 32 is also passable throughthe pipe passageways 16 and 20 in the second direction 36.

The forming assemblies 14 and 18 are each positionable for forming theportions of the pipe 32 passing therethrough in predetermined radii, andthe forming assemblies 14 and 18 are positionable with respect to eachother for forming the portions of the pipe 32 passing through theforming assemblies 14 and 18 through predetermined forming angles, theforming assemblies 14 and 18 cooperating to form the portions of thepipe 32 passing therethrough in predetermined radii throughpredetermined forming angles. Thus, the first forming assembly 14 andthe second forming assembly 18 are each movably connected to the supportstructure 12 so the positions of the forming assemblies 14 and 18 areselectively changeable for selectively changing the orientation of theforming assemblies 14 and 18 relative to each other, thereby selectivelychanging the forming angle through which the pipe 32 is formed as thepipe 32 passes through the forming assemblies 14 and 18.

In the operational embodiment shown in FIGS. 1, 2 and 3 the supportstructure 12, more particularly, includes: an underwater chamber 50,which is mounted on a platform 52. In this embodiment, the base 38, moreparticularly, comprises a wellhead 54, which projects a distance abovethe floor surface 46 of the body of water and through a portion of theplatform 52. The platform 52 is connected to the wellhead 54 at theconnection 40 and the platform 52 is supported generally above the floorsurface 46 via the wellhead 54. The wellhead 54 comprises a portion ofan offshore well and is submersed below the surface 42 of the body ofwater. A seal member (not shown) is disposed between the chamber 50 andthe platform 52 and portions of the seal member sealingly engage thechamber 50 and the platform 52 for providing a relatively fluid-tightseal therebetween. The chamber 50 and the platform 52 cooperate toprovide an enclosed, substantially dry atmosphere, preferably at lowpressure, working environment for workmen.

The chamber 50 is provided with a fluid-tight compartment 56 locatedgenerally within the upper portion of the chamber 50 within whichworkmen may be housed when the chamber 50 is being lowered intoengagement with platform 52. After such engagement, water is removedfrom the lower portion of the chamber 50 and the platform 52 after whichthe workmen may decend into the lower portion, through a hatchedpassageway (not shown), of the chamber 50 and into the platform 52 toperform work on the wellhead 54 and the like. It will be understood, ofcourse, that the compartments can be of varying shapes and sizes, asdesired. Furthermore, a plurality of compartments may be included inchamber 50.

The chamber 50, as illustrated in FIGS. 1, 2 and 3, includes at leastone auxiliary chamber 58 (one additional numbered auxiliary chamberbeing shown in FIG. 1 and two unnumbered auxiliary chambers being shownin FIG. 2, for example), which is connected to the outer surface of thechamber 50. The auxiliary chamber 58 substantially encompasses a space60. A passage 62 is connected between the chamber 50 and the auxiliarychamber 58, the passage 62 being shaped to provide communication betweenthe compartment 56 of the chamber 50 and the space 60 of the auxiliarychamber 58. The passage 62 provide access for workmen to move betweenthe compartment 56 of the chamber 50 and the space 60 encompassed by theauxiliary chamber 58.

With respect to the utilization of the pipe installation system 10 incooperation with the particular support structure 12 shown in FIGS. 1, 2and 3, the first forming assembly 14, more particularly, is disposedwithin the space 60 defined via one of the auxiliary chambers 58 and isremovably and positionably affixed to the auxiliary chamber 58 via aplurality of braces 64 via a swivel connection 65 for example. Thesecond forming assembly 18, more particularly, is removably andpositionably supported within a portion of the platform 52, generallywithin a space 66 formed between a lower portion of the chamber 50 andthe platform 52 via a structure 67, the second forming assembly 18 beingconnected to the structure 67 via a swivel connection 69 for example.The second forming assembly 18 is removably supported within the space66, so it may be removed from the inner portions of the chamber 50 andthe platform 52 for storage outside the support structure 12 when thechamber 50 is being utilized for purposes other than forming pipe at thewellhead or other underwater station. A fluid-tight pipe passageway 68is connected between the auxiliary chamber 58 and the chamber 50 forproviding communication between the spaces 60 and 66 and, moreparticularly, for providing a communication path for the pipe 32 passingfrom the first forming assembly 14 and into the second forming assembly18.

With respect to the specific support structure 12 shown in FIGS. 1, 2and 3, the first forming assembly 14, more particularly, is adjusted toform the pipe 32 passing therethrough at an angle 70 of about 90degrees, the angle 70 being the angle between a centerline axis 72 ofthe pipe passageway 16 through the first forming assembly 14 and acenterline axis 74 of the pipe passageway 20 through the second formingassembly 18. The angle 70 is determined via the orientation (angulardisposition) of the fist and the second forming assemblies 14 and 18.The riser 22 is oriented with respect to the first forming assembly 14such that the centerline axis 72 of the pipe passageway 20 extends at anangle 76 with respect to a centerline axis 78 of the opening 28 throughthe riser 22.

Assuming the pipe 32 is to be passed in a substantially verticaldirection through the riser 22 pipe passageway 28 and the pipe 32 is tobe passed from the second forming assembly 18 along a path oriented atabout 90 degrees with respect to the riser 22 centerline axis 78 forinstalling the pipe along a portion of the floor surface 46 beneath thesurface 42 of the body of water, then, the angle 70 is about 90 degreesand the angle 76 is about 180 degrees. In the last-mentioned operationalembodiment, the pipe 32 is formed at an angle 70 of about 90 degrees viathe first forming assembly 14 and the bent or formed pipe 32substantially is straightened or otherwise formed as desired via thesecond forming assembly 18 so the pipe 32 passed from the second formingassembly 18 extends along a path substantially parallel to the floorsurface 46.

In some applications, it may be desirable to operate the formingassemblies 14 and 18 such that the portion of the pipe 32 passed fromthe second forming assembly 18 and extending along a path generallyparallel to the floor surface 46 includes one or more portions (notshown) formed on radii providing curved sections. The curved sectionportions of the pipe 32 provide relief of undesirable forces acting onthe pipe 32, such as those forces resulting from thermal expansion andcontraction due to differences between the temperature levels of thefluid passing through the pipe 32 and the environment (body of water,for example) surrounding the pipe 32, for example.

As mentioned before, the first and the second forming assemblies 14 and18 are each constructed so that the pipe 32 is passable through the pipepassageways 16 and 20 in the second direction 36. With respect to theone particular operational embodiment referred to before and when thepipe 32 is to be passed through the pipe passageways 16 and 20 in thesecond direction 36, the second forming assembly 18 is adjusted to formthe portions of the pipe 32 passing therethrough at the angle 70, andthe first forming assembly 14 is adjusted to form the portions of thepipe 32 passing therethrough in a manner such that the pipe 32 ispassable from the first forming assembly 14 into and through the riser22 pipe passageway 28. In other words, in this particular application,the second forming assembly 18 bends or forms the pipe 32 passingtherethrough in the second direction 36 at the angle 70 of about 90degrees and the first forming assembly 14 essentially straightens theportions of the pipe 32 passing therethrough in the second direction 36,the pipe 32 then being passed through the riser 22 pipe passageway 28 inthe second direction 36.

The top of a blind ram type of blowin preventer 80 equipped with blindor complete shut-off rams is connected to the second end 26 of the riser22 and is disposed outside the space 60 defined via the auxiliarychamber 58, the riser 22 extending upwardly generally toward the surface42 of the body of water. A ram type blowin preventer 82, equipped withpipe rams sized to fit the pipe 32, is connected to the blowin preventer80 via a conduit 84. The conduit 84 extends through an opening 85 formedthrough the auxiliary chamber 58 and into the space 60, therebydisposing the blowin preventer 82 generally within the space 60, theconduit 84 being sealingly secured to the auxiliary chamber 58 in anysuitable manner, such as by welding, for example, for preventing fluidfrom entering the space 60. An annular blowin preventer 86 is connectedto the ram type blowin preventer 82 and is disposed within the space 60.It should be noted that the blowin preventers 80, 82 and 86 may all bedisposed within the space 60 or outside the auxiliary chamber 58 ifdesired in a particular application, the particular disposition shown inthe drawings representing one preferred embodiment.

A conduit 88 extends through an opening 90 in the platform 52 and theconduit 88 is sealingly secured to the platform 52 in any convenientmanner, such as by welding, for example, one end of the conduit 88 beingdisposed within the space 66 and the conduit 88 providing communicationbetween the space 66 and the water environment outside the supportstructure 12. A flange 91 or other form of connector (not shown) isformed on the end of the conduit 88 which is disposed in the space 66. Ablind ram type of blowin preventer 92 equipped with blind or completeshut-off rams is connected to the flange 91 on the end of the conduit88. A ram type blowin preventer 94 equipped with pipe rams sized to fitpipe 32 is connected to the blowin preventer 94. An annular blowinpreventer 96 is connected to the ram type blowin preventer 94. In onepreferred form, as shown in FIG. 1, each of the blowin preventers 92, 94and 96 is disposed within the space 66, although the blowin preventers92, 94 and 96 may be disposed in the water environment outside theplatform 52 if desired in some particular application, the particulardisposition of the blowin preventers 92, 94 and 96 shown in FIG. 1 beingone preferred disposition.

In one embodiment, it is contemplated that commercially available"blowout" preventers may be utilized for the blowin preventers 80, 82,86, 92, 94 and 96, except in this embodiment, the blowout preventers areinstalled for a different purpose with respect to the commerciallyintended installation, since blowout preventers are designed normallyfor installation on oilwells and the like to prevent fluid from blowingout from a well and, in the present invention, the blowin preventers areutilized to prevent fluid from flowing into the interior of the chambers50 and 58 and space 66. In the present invention, the annular blowinpreventers 86 and 96 are constructed to effect an inward sealing actionfor sealingly engaging the portions of the pipe 32 or other materials,such as a wire line, for example, passing therethrough and the annularblowin preventers 86 and 96 are utilized when the spaces 60 and 66 ofthe chambers 50 and 58 are to be maintained relatively dry orfluid-free. Blowout preventers of the type commercially available fromsuch manufacturers as Hydril Company, and designated by model numberMSP-2000, for example, may be utilized as the annular blowin preventers86 and 96. The ram type blowin preventers 82 and 94 are constructed tosealingly engage the pipe 32 passing therethrough and are also utilizedto effect a seal for preventing fluid from entering the spaces 60 and 66of the chambers 50 and 58 particularly when it is desired to effectrepairs or maintenance on the annular blowin preventers 86 and 96, suchas when changing worn seal elements in the annular blowin preventers 86and 96, for example. Blowin preventers of the type commerciallyavailable from such manufacturers as Cameron Iron Works, Inc. anddesignated by model number Type U, for example, may be utilized as theblowin preventers 82 and 94. The blind ram blowin preventers 80 and 92are constructed to sealingly close the riser 22 pipe passageway 28 andthe opening through the conduit 88, respectively, and are utilized toseal fluid from entering the spaces 60 and 66 of the chambers 50 and 58when repairing, maintaining or installing the blowin preventers 82, 86,94 and 96, such as when changing the seal elements of the ram typeblowin preventers 82 and 94 to sealing engage a different pipe having adifferent outside diameter, or when installing the blowin preventers 82,86, 94 and 96, or at any other time when it is desired to seal theinteriors of the chambers 50 and 58 from the surrounding fluidenvironment and pipe is not being run through pipe installation system10, for example. Blowin preventers of the type commercially availablefrom such manufacturers as Cameron Iron Works, Inc., and designated bymodel number Type U, for example, may be utilized as the blowinpreventers 80 and 92. In one form, the blind ram blowin preventers 82and 94 also include means for cutting the pipe 32 disposed therethrough;however, it is contemplated that such cutting capability of the blowinpreventers 82 and 94 would be utilized for emergency use only and thesystem would include other conventional cutting means (not shown) forcutting the pipe 32 during the normal operation. The blowin preventers80, 82, 86, 92, 94 and 96 are preferably constructed to be actuated forsealing engagement from a remote location, such as via a hydraulic typecontrol system (not shown), for example. Further, the blowin preventers82, 86, 94 and 96 each, either singularly or in combination, function toaccomplish the stripping requirement described in U.S. Pat. No.3,754,404.

A removable pipe plug (not shown) is disposed in the opening through theconduit 88 to prevent fluid from entering the space 66 and the chambers50 and 58 through the conduit 88 prior to the installation of blowinpreventers 92, 94 and 96 and the forming assembly 18. After the blindram blowin preventer 92 has been connected to flanged end of the conduit88, as shown in FIG. 1, the pipe plug can be removed and the blowinpreventer 92 functions to seal the conduit 88 during the installation ofthe other blowin preventers 94 and 96 and the second forming assembly18. The blind ram blowin preventer 80 prevents fluid from entering thechamber 58 via the conduit 84, and the other blowin preventers 82 and 86and the first forming assembly 14 can be installed or removed at varioustimes depending upon the particular operation.

The present system, as shown in FIG. 1, is suitable for installing pipeat underwater depths to 250 feet and greater. After completion ofdrilling all or a portion of the well utilizing the wellhead 54 and theplatform 52, the chamber 50 is lowered from a surface vessel (not shown)by a pipeline 98 and sealingly mounted in engagement with platform 52.It will be appreciated that riser 22 may be run simultaneously withpipeline 98 or independently after chamber 50 is run, and the riser 22then is connected to the blowin preventer 80. After the chamber 50 hasbeen sealingly engaged with the platform 52, the blind ram blowinpreventer 80 is operated as may be required and water is removed fromthe chamber 50, the auxiliary chambers 58 and the riser 22, to establisha relatively dry and preferably low pressure environment therein.Thereafter, the workmen descend into the lower portion of the chamber50, and install the blowin preventer 92. The pipe plug (not shown) inthe conduit 88 is removed after the blowin preventer 92 has been closed.The workmen then secure the forming assemblies 14 and 18 in an operativeposition along with the remaining components of the pipe installationsystem 10.

Thereafter, pipe 32 is lowered downwardly in the first direction 34 fromthe surface vessel (not shown) through riser 22 pipe passageway 28. Inone preferred embodiment, the riser 22 has a water-tight constructionand one end of the riser 22 extends above the surface 42 of the body ofwater to prevent water from entering the passageway 28. As shown on thedrawings, the pipe 32, after passing through the blowin preventers 80,82 and 86, passes through the first forming assembly 14 wherein the pipe32 is formed in a predetermined radius for passing the pipe from thefirst forming assembly 14 through the passage 68 and into the secondforming assembly 18. The passageway 68 is only a passageway, and it doesnot function as a guide to aid in forming the pipe 32. The portions ofthe pipe 32 passing through the second forming assembly 18 essentiallyare straightened or formed as otherwise desired and the pipe 32 ispassed from the second forming assembly 18 through the blowin preventers92, 94 and 96 and through the conduit 88, the blowin preventers 94 and96, either singularly or in combination, maintaining a fluid-tight sealabout the portions of the pipe 32 passing therethrough to maintain thesealed integrity of the chamber 50.

The leading end of the pipe 32 preferably is plugged. A flexible membersuch as a wire line is attached to the leading end preferably prior tofeeding the pipe 32 from the second forming assembly 18 into the blowinpreventers 92, 94 and 96, and the wire line extends generally along thefloor surface 46 of the body of water to a power means, such as a winch,for example (not shown) located at some remote installation. Thereafter,the winch is activated to pull the wire line and leading end of the pipe32 to a remote structure or station (not shown).

Thereafter, the pipe 32 is pressure tested to make certain that the pipe32 still has integrity and has not been broken or otherwise damaged inthe coarse of the pulling operation. The pipe 32 also can be tested fordistortion, if desired. The blowin preventers 94 and 96, eithersingularly or in combination, are closed inwardly on the pipe 32 whenthe forming of the pipe via the forming assemblies 14 and 18 occurs inde-watered chambers 50 and 58. The riser 22, after having been drainedif necessary, prevents the flow of water into chambers 50 and 58 therebyeliminating the need for closing the blowin preventers 82 and 86. Theblowin preventers 82 and 86 are available for closing in the event ofdamage or otherwise loss of fluid (water) tight integrity of the riser22. This feature of the riser 22 reduces the wearing of the sealingelements of the blowin preventers 82 and 86 and further reduces thechances of inadvertently flooding the chambers 50 and 58 which couldresult in disastrous consequences. It will be appreciated that theforegoing procedure, utilizing blowin preventers 80, 82, 86, 92, 94 and96 and the riser 22 affords the utmost of safety with respect toinadvertently flooding spaces 60 and 66 while making pipe installations,as compared to such stripping operations as described in U.S. Pat. No.3,754,404, for example. Yet, the procedure of the present inventionstill requires the pipe 32 to be in slidable or rubbing contact with theseal members in the blowin preventers 94 and 96 and possibly those inthe blowin preventers 82 and 86 over nearly, if not all, the length ofthe pipe being installed. Such sliding contact causes wear and reducesthe operating life of the sealing elements and increases the chances forinadvertently flooding spaces 60 and 66 which can lead to injury orpossibly loss of life of workmen in these spaces. Use of remote controlsfor the forming assemblies 14 and 18 and the blowin preventers makes itpossible for the workmen to leave these chambers while running the pipe32 except for performing maintenance operations on equipment.Additionally, these features permit the flooding of the spaces 60 and 66when running pipe 32 and further permits the complete opening of allblowin preventers and eliminating the wear problem altogether.Therefore, the present invention contemplates the inclusion of controlsfor remotely operating the forming assemblies 14 and 18 and blowinpreventers 80, 82, 86, 92, 94 and 96 in one embodiment. Further, afterpipe 32 has been run and after the chambers 50 and 58 have beenresealed, if necessary, and conduit 88 has been sealed around pipe 32(sealing element not shown) and the chambers have been dewatered, theblowin preventers 92, 94 and 96 are now ready to be removed.

Thereafter, workmen sever the pipe 32 and the unused pipe 32 then ispulled back upwardly in the second direction 36 through the formingassemblies 14 and 18, the second forming assembly 18 being adjusted tobend the pipe 32 in a desired radius and the first forming assembly 14essentially straightening the pipe 32 for passing the unused pipe 32through the riser 22 back to the surface vessel or the like (not shown).It should be noted that, in some applications, the unused pipe 32 willbe pulled back in the second direction 36 only a distance sufficient toremove the unused pipe 32 from the chamber 50 and dispose such unusedpipe 32 generally within the auxiliary chamber 58. Further, the formingassemblies 14 and 18 can be utilized to pull or move all or a portion ofthe pipe 32 in the second direction 36 back through the formingassemblies 14 and 18 for withdrawing the pipe 32 from the pipeinstallation system 10.

Blowin preventers 92, 94 and 96 are removed from flange 91 and theterminal end of pipe 32 is connected to the well or other apparatus. Itis a feature of this invention that such terminal connection is made ina substantially dry atmosphere using conventional means such as welding,for example. As will be appreciated, this invention also permitsutilization of the chamber 50, or like chambers, at other underwaterstations to make terminal connections or to connect other electrical orhydraulic control lines, for example.

It will be appreciated that the foregoing procedure may be repeated toinstall a multiplicity of pipelines as well as control lines(electrical, hydraulic and the like) between the two underwater stations(support structures) for example. For example, the forming assemblies 14and 18 each can be movably positioned via the swivel connections 65 and69, respectively, for passing the pipe through additional conduits 97and 99 (shown in dashed-lines in FIG. 2). By the same token, a remotestation may incorporate more than one conduit like the three conduits88, 97 and 99 for receiving pipes, if desired in a particularapplication.

A significant aspect of the present invention is the inclusion of theriser 22 through which the pipe 32 is passed into and through theforming assemblies 14 and 18. Without the riser 22 and without tension,the compressive stesses in the pipe 32 due to its own weight can begreat enough to buckle the pipe 32 at some place generally between thesurface 42 of the body of water or, in other words, between theinstallation generally near the surface 42 such as a vessel, forexample, and the chambers 50 and 58, for example, as the pipe 32 ispassed through the forming assemblies 14 and 18. Further, in the absenceof the riser 22, a pulling means, such as, for example, the wire line(not shown) which is attached to the end of the pipe 32 for pulling thepipe 32, would be pulled under tension in the first direction 34 towardthe installation (not shown) remotely located with respect to thesupport structure 12, at the same time the pipe is maintained undertension upwardly generally in the second direction 36 and such opposingforces would result, not only in a higher pulling force on the leadingend of the pipe 32, but also in relatively high bending moments in thechamber 50 and platform 52, at the connection of the plafform 52 to thewellhead 54, in the base 38 and in higher soil stresses in the floor 44.The pulling forces can be reduced via the present invention utilizingthe proper combination of compression and tension forces to provide thethrust to pass the pipe 32 through the forming assemblies 14 and 18.

The utilization of the riser 22 provides lateral stability to the pipe32 which permits the application of a compressive force in pipe 32 whenpipe 32 is being passed in the first direction 34. The use ofcompression in pipe 32 for thrusting pipe 32 through the formingassemblies 14 and 18 reduces or substantially eliminates the need forapplying tensile force at the exit end of the second forming assembly 18to provide the thrust. This feature reduces the strength requirement ofthe pulling means for moving the pipe along the sea floor to the extentof the reduction of such tensile thrust force.

The nature of the riser 22 requires an application of tensile force atthe first end 24 of riser 22, such tensile force diminishing inmagnitude (such reduction of the tensile force being generallyequivalent to the weight of the riser 22 in water) along riser 22 fromthe first end 24 toward the second end 26. However, good practicegenerally requires that such tension force is not reduced to zero. Thisapplication of tensile force protects the riser 22 from environmentalforces, such as current, surface vessel motion and the like, forexample. The excess tension is supported by support structure 12 andproduces a bending moment throughout the support structure 12, which canbe most critical in the area of the base 38. Such bending moment mayfurther increase soil stresses via base 38, possibly to the point offailure.

Compression in the pipe 32 reacted by the forming assemblies 14 and 18tends to offset the bending moment resulting from the tension in theriser 22, as described before. The reduction or elimination of thetensile thrust force at the exit end of the second forming assembly 18generally tends to be additive to the bending moment created by thetension in the riser 22 and thus the elimination or reduction of thistensile force is beneficial to the operation of the pipe installationsystem 10 of the present invention.

In addition to the foregoing, the moment in the chamber 50 and in theplatform 52, at the connection of the platform 52 to the wellhead 54,and in the base 38, for example, can be reduced by connecting one end ofa tension member 106, such as a wire line, for example, to the supportstructure 12, having a moment arm generally located on the opposite sideof the chamber 58 with respect to the location of the connection of theriser 22 to the support structure 12. The tension member 106 extendsfrom the support structure 12 to a structure, such as a vessel (notshown) located on or near the surface 42 of the body of water. Forexample, the tension member 106 can be connected to the top portion ofan auxiliary chamber 108 at a connection 109, the auxiliary chamber 108is being connected to the chamber 50 and disposed on the chamber 50generally opposite the auxiliary chamber 58, as shown in FIGS. 1 and 2.

It should be noted that the reactions exerted on the chamber 50 by thecompressive forces in the pipe 32 and possibly the tension force exertedby the riser 22 will vary during different phases of the operation ofthe pipe installation system 10. The moments referred to above also willvary during the operation. One advantage of the tension member 106 isthat the force exerted on the support structure 12 can be adusted,thereby permitting the moment to be controlled within limits during allphases of the operation of the pipe installation system 10.

Application of tension in the riser 22 and the tension member 106increases the moments in the support structure 12, for example, in thearea of the passageway 62, between the compartment 56 and the space 60,which may result in local design and fabrication problems. Theapplication of tension in the riser 22 and the tension member 106 can becontrolled to virtually eliminate bending moments in the connection 40,in the base 38 and the corresponding reactive loads in the floor 44resulting from the pipe laying operation contemplated via the presentinvention. The design and fabrication of a suitable structure forreacting bending moments in the area of the passageway 62 is simpler, ascompared with the design and fabrication problems of a suitablestructure in the area of the lower portion of the support structure 12,the connection 40 and in the base 38. The design of the base 38 isdependent upon the soil strength and other characteristics of the floor44. The sea floor 44 soil strengths vary radically and the methods formeasuring such strengths are not precise and, therefore, it is prudentto minimize the soil load. Soil failure can result in the failure of thebase 38 which results in problems of great magnitude.

The capability of the riser 22 to prevent buckling of the pipe 32 isdependent on the clearance between the inner peripheral surface definedvia the opening 28 through the riser 22 and the outer peripheral surfaceof the pipe 32, and the compression force in the pipe 32. If thisclearance is too large, the pipe 32 may buckle within the riser 22.However, this possible problem is eliminated by simply selecting theproper size of the riser 22 with respect to any particular size of thepipe 32. However, for convenience, the present invention alsocontemplates applications wherein the same riser 22 is utilized withdifferent sizes of the pipe 32, at least within a certain range of pipesizes, and, in this particular application, the clearance between theriser 22 and the pipes will not be optimum for all of the pipe sizes. Inthis last-mentioned application, properly spaced inserts, which may beremovable, can be inserted within the opening 28 of the riser 22, eachinsert or bushing being sized and spaced to optimize the clearancerelationship between the inner peripheral surface defined via theopening through each insert and the outer peripheral surface of any oneof the several pipes to minimize the possibility of the pipe 32 bucklingfrom the compression.

In summary, the various factors controlling the total moment of thesystem of the present invention utilizing the riser 22 are subject todesign control and the utilization of the riser 22 permits the pipeinstallation system 10 to be constructed in a manner effecting a reducedtotal moment and a reduced tension force required to pull the pipe 32,as compared to a system without the riser 22. Further, the riser 22provides a guide path for pipe 32 and functions to substantially reducethe possibilities of the pipe 32 buckling at some point generallybetween the surface 42 and the position where the pipe 32 enters thefirst forming assembly 14 by providing lateral support for pipe 32 whilepassing in the first direction 34.

In one embodiment, the leading end of the pipe 32 is sealingly closedand the pipe 32 is filled with air or gas. In this manner, the bouyancyof the portions of the pipe 32 extending through the body of water isincreased, which reduces the effective weight of the pipe 32 in the bodyof water, thereby reducing the friction force between the pipe 32 andthe floor surface 46 to facilitate the pulling or moving of the pipe 32along the floor surface 46.

FORMING ASSEMBLIES

As shown in FIGS. 1 through 6, the first and the second formingassemblies 14 and 18 are constructed almost exactly alike, in onepreferred form, and each of the forming assemblies 14 and 18 includes aframe assembly 110, having a first side 112, a second side 114, a firstend 116 and a second end 118. The frame assembly 110 provides thestructural support for the various components of the forming assemblies14 and 18. As shown more clearly in FIG. 4, the frame assembly 110includes at least two support frames 120 and at least one spacer frame122, each spacer frame 122 being connected between two support frames120 for spacing the support frame 120 a predetermined distance apartgenerally between the opposite ends 116 and 118 of the frame assembly110.

At least two surfaces are supported on the frame assembly 110 forengaging the portions of the pipe 32 passing therethrough and thesurfaces are spaced on the frame assembly 110 in predeterminedorientations for forming the portions of the pipe 32 passingtherethrough in a predetermined radii. More particularly and in apreferred embodiment, three surfaces are supported on the frame assembly110 for engaging the portions of the pipe 32 passing therethrough in thefirst direction 34 and causing the pipe 32 to be formed in predeterminedradii, and three other surfaces are supported on the frame assembly 110for engaging the portions of the pipe 32 passing therethrough in thesecond direction 36 and causing the pipe 32 to be formed in apredetermined radii. With respect to this last-mentioned embodiment, twoof three surfaces are positioned on the frame assembly 110 for engagingthe portions of the pipe 32 passing therethrough and imposing a force onsuch portions in one direction, and one of the three surfaces ispositioned on the frame assembly 110 for engaging the portions of thepipe 32 passing therethrough and imposing a force on such portions in adirection, generally opposite the direction of the force imposed via thefirst two mentioned surfaces.

Referring more particularly to the preferred embodiment of the presentinvention, a plurality of rollers 124 are supported on the frameassembly 110 and each roller 124 has an outer peripheral surface 126. Asshown more clearly in FIGS. 1 and 3, six rollers 124 are supported onthe frame assembly 110 (the six rollers being designated via thereference numerals 124A, 124B, 124C, 124D, 124E and 124F, and the outerperipheral surfaces of the rollers 124 are designated via the referencenumerals 126A, 126B, 126C, 126D, 126E and 126F). The rollers 124A, 124B,and 124C, are positioned and oriented on the frame assembly 110 suchthat the outer peripheral surfaces 126A, 126B and 126C, respectively,engage the portions of the pipe 32 passing therethrough in the firstdirection 34, and the rollers 124D, 124E and 124F are each oriented andpositioned on the frame assembly 110 such that the outer peripheralsurfaces 126D, 126E and 126F, respectively, each engage portions of thepipe 32 passing therethrough in the second direction 36. The outerperipheral surfaces 126 of the rollers 124 define the surfaces, referredto before, for engaging the portions of the pipe 32 passing therethroughand forming such portions in predetermined radii.

As shown more clearly in FIG. 4, the rollers 124A and 124D are eachpositionably connected to the support frame 120A; the rollers 124B and124E are each positionably connected to the support frame 120B; and therollers 124C and 124F are each positionably connected to the supportframe 120C.

As shown more clearly in FIGS. 4, 5 and 6, each support frame 120 hasopposite ends 132 and 134, opposite sides 136 and 138, a first face 140and a second face 142. A first channel 144 is formed through the firstface 140 and extends generally between the opposite ends 132 and 134. Asecond channel 146 is formed through a portion of the first face 140 andextends generally between the opposite ends 132 and 134, the firstchannel 144 being disposed generally near the end 134 and the secondchannel 146 being disposed generally near the opposite end 132. Thesupport frame 120 generally encompasses and defines an open space 148,and the first and the second channels 144 and 146 each intersect aportion of the open space 148.

A bar 150 is disposed generally within the open space 148 of the supportframe 120. The bar 150 has opposite ends 152 and 154 and the bar 150 issupported within the open space 148, generally below the first and thesecond channels 144 and 146.

One end of a first shaft 156 is secured to the bar 150, generally nearthe end 154 thereof, and the first shaft 156 extends a distance from thebar 150, the first shaft 156 extending through and being disposedgenerally within the first channel 144. One end of a second shaft 158 issecured to the bar 150, generally near the end 152 thereof, and thesecond shaft 158 extends a distance from the bar 150, the second shaft158 extending through and being supported generally within the secondchannel 146.

A first plate 160, having an opening 162 formed through a centralportion thereof, is secured to the bar 150 and the first shaft 156extends through the opening 162 (shown more clearly in FIG. 6). As shownmore clearly in FIG. 5, portions of the first plate 160 slidingly engageportions of the first face 140 of the support frame 120, generally nearthe first channel 144, the engagement between the first plate 160 andthe support frame 120 cooperating to movably support the bar 150 withinthe open space 148. A second plate 164, having an opening 166 extendingthrough a central portion thereof, is secured to the first face 140 ofthe support frame 120. The second shaft 158 extends through the opening166 in the second plate 164 and portions of the second plate 164 engageportions of the first face 140 of the support frame 120, generallyadjacent to the second channel 146, the second plate 164 cooperatingwith the first plate 160 to support the bar 150 within the open space148.

One of the rollers 124 is journally connected to the first shaft 156 andanother of the rollers 124 is journally connected to the second shaft158. The rollers 124 are each constructed exactly alike, and one typicalroller 124 is shown in section in FIG. 6. Each roller 124 includes a hub168, which is connected to one of the shafts 156 or 158 via a bearingassembly 170, each bearing assembly 170 journally supporting one of thehubs 168 on one of the shafts 156 or 158. Each roller 124 also includesa roller base 172 which is removably connected to the hub 168 via aplurality of fasteners 174.

An elastomeric member 176 is secured to the outer peripheral surface ofeach roller base 172 and each elastomeric member 176 extends annularlyabout one of the roller base 172. Each elastomeric member 176 has anouter peripheral surface and a recess 180 is formed in the outerperipheral surface 178, each recess 180 extending annularly about one ofthe rollers 124. Each of the recesses 180 is formed on a curve or radiusfor engaging a portion of the pipe 32.

When the elastomeric member 176 engages the pipe 32, the elastomericmember 176 is compressed, thereby temporarily elastically deformingportions of the elastomeric member 176 and increasing the surface areaof the portions of the elastomeric member 176 engaging the pipe 32. Theforce exerted on the pipe 32 via the elastomeric member 176 is greatestnear the central portion of the contact area between the elastomericmember 176 and the pipe 32 and the force decreases from the centralportion toward the outer limit of the contact area between theelastomeric member 176 and the pipe 32 in directions parallel to anaxially extending centerline of the pipe 32. If the portions of therollers 124 engaging the pipe 32 were constructed of a non-elastomericor solid material, each of the rollers 124 would engage the pipe 32essentially at a point of contact or, if the portions of the rollers 124engaging the pipe 32 were formed on a radius, then each roller 124 wouldengage the pipe essentially along a line of contact, the length of theline of contact depending upon the degree to which the roller 124contact surfaces conforms to the outer peripheral surface of the pipe32.

If the pipe 32 contains some deformity, such as a weld bead, forexample, and the portions of the rollers 124 engaging the pipe 32 wereconstructed of a solid material, the forces imposed on the pipe 32 viathe forming assemblies 14 and 18 would increase when contactinglyengaging such deformities and, as a result, the forces imposed on thepipe 32 as the pipe 32 is passed through the forming assemblies 14 and18 will increase sharply even to the point of locally deforming pipe 32.The elastomeric member 176 deforms in the presence of pipe deformities,such as the weld bead, for example, without substantially changing theoverall force on pipe 32. In the contact area, it has been found thatthe forces imposed on the pipe 32 as the pipe 32 is passed through theforming assemblies 14 and 18 remains sufficiently uniform when theportions of the pipe 32 containing the deformities, such as the weldbeads, for example, are passed through the forming assemblies 14 and 18.Thus, the construction of the rollers 124 of the present invention,having the elastomeric member 176 forming the engaging or contactingsurfaces of the forming assemblies 14 and 18, substantially reduces orlimits any undesired deformation of the pipe 32 resulting when suchsurfaces engage portions of the pipe 32 containing deformities (the weldbeads, for example).

The rollers 124 each rotate about one of the shafts 156 or 158, and theshafts 156 and 158 are secured to the bar 150 such that the shaft 156 isspaced a distance 182 from the shaft 158, as shown in FIG. 6. Theportions of the outer peripheral surfaces 178 formed via the recesses180 are spaced apart a distance 184. The rollers 124 are sized such thatthe distance 184 is larger than the outer peripheral diameter of thepipe 32, which is useful in removing the pipe 32 from the formingassemblies 14 and 18 as will be described below in connection with FIGS.17, 18, 19 and 20.

The elastomeric member 176 elastically deforms when in forming contactwith pipe 32, thereby increasing the surface area of contact. The radiusor recess 180 further increases the surface area contact. The member 176and the recess 180 cooperate to reduce the unit surface bearing pressureon the surface of pipe 32, and to reduce substantially the chances ofdamaging pipe 32 by excessive surface bearing loads. Additionally,elastomeric member 176 locally deforms when contacted by deformities onpipe 32, such as a weld bead, for example, without substantiallychanging the unit bearing pressure on pipe 32.

The distance 182 is fixed via the position of the shafts 156 and 158 onthe bar 150; however, the distance 184 can be changed selectively byreplacing the rollers 124 with other rollers 124 having a different(larger or smaller) diameter. Thus, the forming assemblies 14 and 18 canbe modified to accommodate and receive pipes 32 of different outerperipheral diameters by simply replacing the rollers 124 and the rollers124 are mounted on cantilevered shafts 156 and 158 to permit theconvenient removal and replacement thereof by simply removing thefasteners 174, thereby disconnecting the roller base 172 from the hub168 or the entire rollers 124 can be removed from and installed on theshafts 156 and 158 via the removal or installation of retaining rings186. Also, the distances 182 and 184 can be changed by removing the bar150 and replacing the removed bar 150 with a bar 150 having the desireddistances 182 and 184. The bar 150 can be removed by simply removing therollers 124 and the plates 160 and then removing the bar 150 through anaccess opening 188 formed through the second face 142. The cantileveredshafts 156 and 158 and the constuction of the rollers 124 also permitsthe convenient removal and replacement of the roller bases 172 bydisconnecting and connecting the roller base 172 and the hub 168 via thefasteners 174 for repairing or replacing the elastomeric member 176.

A threaded drive shaft 190 is journally connected to the support frame120 and a portion of the drive shaft 190 extends through a threadedopening 192 formed through a portion of the bar 150. A driver 194 isconnected to the drive shaft 190 and the driver 194 is constructed torotatingly drive the drive shaft 190 in a first direction of rotationand in an opposite second direction. As the drive shaft 190 isrotatingly driven in the first direction of rotation, the bar 150 ismoved in a first direction 196 within the space 148 via the threadedengagement between the drive shaft 190 and the bar 150 and, as the driveshaft 190 is rotatingly driven in the second direction, the bar is movedin the second direction 198 via the threaded engagement between thedrive shaft 190 and the bar 150. Thus, the position of the rollers 124can be changed selectively via the drive shaft 190.

The driver 194 may be a hydraulic or electric motor or any other driversuitable for rotatingly driving the drive shaft 190 to move the bar 150in the directions 196 or 198. In one embodiment, a control unit 200 isconnected to the driver 194 via a control line 202 for actuating thedriver 194 to rotate the driver shaft 190 to move the bar 150 in thefirst and the second directions 196 and 198 from a remote location, suchas from a vessel on the surface 42 of the body of water, for example.The utilization of the threaded driver shaft 190 to position the bar 150provides a "step less" type of positioner for allowing the positioningof the bar 150 and the roller 124 connected thereto in relatively smallincrements, which is beneficial in controlling the bend radius of thepipe 32 passing through the forming assemblies 14 and 18. In onepreferred form, the control unit 200 includes a position indicatingdevice having a portion connected to either the driver shaft 190 or thedriver 194 for sensing and indicating the position of the bar 150. Inthis manner, the driver 194 can be controlled from a remote location viaa control unit 200 with the position indicating device providing thenecessary information to the operator for remotely positioning the bar150 in predetermined locations.

It will be understood, of course, that other means may be utilized toposition the rollers 124 in the desired location. Thus, for example, thedrive shaft 190 can be rigidly attached to the bar 150 and the driver194 can be adapted to rotate a suitable engaging device, such as a nut,for example, to position the bar 150 and the roller 124 in the desiredlocation.

Assuming the pipe 32 is passing through the forming assembly 14 or 18shown in FIG. 4 and it is desired to form the pipe 32 in a predeterminedradius to provide the bent pipe 32 passing from second end 118 of theframe assembly 110 in the second direction 34, the control unit 200 isactivated for causing the driver 194 on the support frame 120A to movethe bar 150 supporting the rollers 124A and 124D to a position whereinthe elastomeric member 176 of the roller 124A engages the pipe 32imposing a force on the engaged portions of the pipe 32 in a generaldirection 204, the elastomeric member 176 of the roller 124D beingspaced a distance from pipe 32 in this operative position of the rollers124A and 124D. Further, the control unit 200 is activated for causingthe driver 194 on the support frame 120B to move the bar 150 supportingthe rollers 124B and 124E to a position wherein the elastomeric member176 of the roller 124B engages the pipe 32 imposing a force on theengaged portions of the pipe 32 in a general direction 206, theelastomeric member 176 of the roller 124E being spaced a distance frompipe 32 in this operative position of the rollers 124B and 124E. Thecontrol unit 200 is activated for causing the driver 194 on the supportframe 120C to move the bar 150 supporting the rollers 124C and 124F to aposition wherein the elastomeric member 176 of the roller 124C engagesthe pipe 32 imposing a force on the engaged portions of the pipe 32 in ageneral direction 208, the elastomeric member 176 of the roller 124Fbeing spaced a distance from the pipe 32 in this operative position ofthe rollers 124C and 124F. The exact position of the rollers 124A, 124Band 124C determines the radius on which the portions of the pipe 32passing therebetween and the radius can be changed selectively bypositioning the rollers 124A, 124B and 124C utilizing the drivers 194which, in one embodiment, are controlled remotely via the control unit200.

Assuming the pipe 32 is passing through the forming assembly 14 or 18shown in FIG. 4 and it is desired to form the pipe 32 to provide anessentially straight pipe 32 passing from the first end 116 of the frameassembly 110 in the first direction 36 (the pipe 32 passing into thesecond end 118 being bent as shown in FIG. 4), the control unit 200 isactivated for causing the driver 194 to move the bar 150 supporting therollers 124A and 124D to a position wherein the elastomeric member 176of the roller 124D engages the pipe 32 imposing a force on the engagedportions of the pipe 32 in the general direction 210, the elastomericmember 176 of the roller 124A being spaced a distance from the pipe 32in this operative position of the rollers 124A and 124D. Further, thecontrol unit 200 is activated for causing the driver 194 on the supportframe 120B to move the bar 150 supporting the rollers 124B and 124E to aposition wherein the elastomeric member 176 of the roller 124E engagesthe pipe 32 imposing a force on the engaged portions of the pipe 32 inthe general direction 212, the elastomeric member 176 of the roller 124Bbeing spaced a distance from the pipe 32 in this operative position ofthe rollers 124B and 124E. The control unit 200 is activated for causingthe driver 194 on the support frame 120C to move the bar 150 supportingthe rollers 124C and 124F to a position wherein the elastomeric member176 of the roller 124F engages the pipe 32 imposing a force on theengaged portions of the pipe 32 in a general direction 214, theelastomeric member 176 of the roller 124C being spaced a distance fromthe pipe 32 in this operative position of the rollers 124C and 124F. Theexact position of the rollers 124D, 124E and 124F determines the radiuson which the portions of the pipe 32 passing therebetween and the radiuscan be changed selectively by positioning the rollers 124D, 124E and124F utilizing the drivers 194 which, in one embodiment, are controlledremotely via the control unit 200.

The pipe passageways 16 and 20 through the forming assemblies 14 and 18,respectively, are each defined as the axial centerline of the portion ofthe pipe 32 passing through the forming assembly 14 and 18, generallybetween the opposite ends 116 and 118 of the frame assemblies 110. Sincethe pipe 32 is engaged via three rollers 124 which are offset withrespect to each other, it will be apparent that the axially extendingcenterline of the portions of the pipe 32 passing through the formingassemblies 14 and 18 is curved in different directions at differentpositions within the forming assemblies 14 and 18. Thus, the pipepassageways 16 and 20, as shown in FIG. 1, more particularly, representsthe average straight centerline of space between the rollers 124 whichare positioned for contacting the portions of the pipe 32 passingthrough the forming assemblies 14 and 18.

Utilizing the riser 22, the portion of the pipe 32 extending between thefirst and the second ends 24 and 26 of the riser 22 can be placed incompression for driving the pipe 32 through the forming assemblies 14and 18 since the riser 22 functions to reduce substantially thepossibility of the pipe 32 buckling when exposed to such compression,thereby eliminating a requirement for rotating the rollers 124 via somedriving means.

Since the rollers 124 are rotatingly supported, the friction resultingfrom the engagement between the surfaces 126 of the rollers 124 and thepipe 32 substantially is reduced as compared to the friction utilizingstationary surfaces. The reduction in friction achieved utilizing therotatingly supported rollers 124 reduces the need for rotatingly drivingthe rollers 124. However, in one form, the rollers 124 can be rotatinglydriven (not shown) to drive the pipe 32 through the forming assemblies14 and 18 and, in this embodiment, it is desirable to position all sixof the rollers 124 in each of the forming assemblies 14 and 18 to engagethe portions of the pipe 32 passing therethrough, the pairs of rollers(124A and 124D, 124B and 124E, and 124C and 124F) cooperating to drivethe pipe 32 through the forming assemblies 14 and 18. In thislast-mentioned alternative embodiment, it should be noted that it is notnecessary to contact the pipe 32 with all six rollers 124 for thepurpose of forming the pipe 32; however, the contacting of the pipe 32with all six of the rollers 124 will add some support to minimizepossible flattening or distortion of the pipe 32.

As the pipe 32 passes through the forming assemblies 14 and 18 in eitherthe first or the second direction 34 or 36, the pipe 32 is contacted viathree of the rollers 124 for the purpose of forming the pipe 32. In onealternate embodiment, the rollers 124 can be positioned on each formingassembly 14 and 18 such that the pipe 32 is contacted via all six of therollers 124 as the pipe 32 passes through ether one of the formingassemblies 14 or 18. In this alternate embodiment, three of the rollers124 contact the pipe 32 for the purpose of forming the pipe 32 and theother three rollers 124 cooperate to support the portions of the pipe 32being formed and minimize possible flattening or distortion of the pipe32.

In one other alternate embodiment (not shown), each of the rollers 124on each support frame 120 can be mounted individually on a bar, similarto the bar 150, and each roller 124 can be moved individually indirections 196 and 198 via drive means, such as the drive shaft 190, thedriver 194 and the control unit 200, for example. In this manner, eachof the six rollers 124 is moved independently via one or more drivemeans for independently controlling the position of each of the sixrollers 124, which may be desired in some applications.

It should be noted that the spacer frames 122A and 122B are removablyconnected to the support frames 120A, 120B and 120C. In this manner, thesupport frames 122A and 122B can be removed and replaced with spacerframes of a different size for varying the distance between supportframes 120A, 120B and 120C. Thus, in accordance with the presentinvention, the distance between the spacer frames 120A and 120B and thedistance between the spacer frames 120B and 120C can be varied byutilizing different size spacer frames 122A and 122B for maximizing theforming efficiency of the forming assemblies 14 and 18 with respect toforming pipes of different sizes, different wall thickness or differentstructural properties, for example, since less overall force is requiredto form a pipe or the like as the distances between the support frames120A, 120B and 120C is increased within certain limits (the distancesbeing limited via the spaces 60 and 66 in the embodiment of theinvention shown in FIGS. 1, 2 and 3).

Experiments have shown that position adjustments of the rollers 124 onthe first forming assembly 14 change the stress level in the pipe 32which changes the reactive forces on the rollers 124 in the secondforming assembly 18. In a like manner, position adjustments of therollers 124 on the second forming assembly 18 results in a change of thereactive forces on the rollers 124 in the first forming assembly 14.

Although the forming assemblies 14 and 18 are referred to herein as a"first" forming assembly 14 and a "second" forming assembly 18, theforming assemblies 14 and 18 cooperate as a unit for forming the pipe 32in predetermined radii through predetermined forming angles. In someapplications, some of the rollers 124 shown in the drawings supported onthe first forming assembly 14 can be located on the second formingassembly 18 and, in some other applications, some of the rollers 124shown in the drawings supported on the second forming assembly 18 can besupported on the first forming assembly 14, for example. Further, all ofthe rollers 124 can be supported on a single frame in lieu of the twoframe assemblies 110 shown in the drawings, if desired in someapplications. In other words, it is the relative position of theoperative rollers 124 which cause the pipe 32 to be formed inpredetermined radii through predetermined forming angles and the twoseparate frame assemblies 110 merely illustrates one preferred structurefor supporting the rollers 124.

EMBODIMENT OF FIGURES 7 AND 8

As mentioned before, the pipe installation system 10 of the presentinvention is utilized for interconnecting wellheads or other stationswith manifolds or other stations. An example of one such possibleinterconnection is diagrammatically illustrated in FIGS. 7 and 8,wherein the pipe 32 has been formed via the forming assemblies 14 and18, installed in the support structure 12 (FIG. 7), extended along apath near the floor surface 46, and installed in another supportstructure 12A. More particularly, the installation of control lines,such as electrical cables and hydraulic conduits, for example, betweentwo underwater stations (support structures 12) in accordance with oneaspect of the present invention is diagrammatically illustrated in FIG.7, and the control lines are shown in one installed arrangement at thesupport structure 12A (FIG. 8).

A pipe, such as the pipe 32, for example, is installed between thesupport structure 12 and the remote support structure 12A by passing thepipe 32 through the riser 22 and through the forming assemblies 14 and18 in a manner described before with respect to FIG. 1. The pipe 32 ispassed from the support structure 12 through the conduit 88 and along apath generally parallel with the floor surface 46 toward the remotesupport structure 12. A wire line (not shown) is attached to pipe 32 andto a pulling mechanism (not shown) for pulling the pipe 32 from thesupport structure 12 to the remote support structure 12A, the wire line(not shown) pulling a portion of the pipe 32 through the conduit 88A.After the pipe 32 has been pulled through the conduit 88A, the portionof the pipe 32 extending through the conduit 88A can be cut or severedto some predetermined length, thereby leaving one end portion of thepipe 32 disposed at the remote support structure 12A, the remainingportion of the pipe 32 extending between the support structures 12 and12A and through the support structure 12 terminating with the end of thepipe 32 which is connected to a power or control line feed assembly 230.

After the pipe 32 has been installed between the two support structures12 and 12A, one end of the pipe 32 is connected to the power or controlline feed assembly 230 which seals the end of the pipe 32 connectedthereto, while allowing a control line 232 (shown in dashed-lines) to bepassed in sealing engagement therethrough into and through the openingthrough the pipe 32, as diagrammatically shown in FIG. 7. A leading end234 of the control line 232 is connected to a piston 236, which is sizedto be inserted into and slidingly moved through the opening in the pipe32 during the installation of the control line 232, the piston 236including portions (not shown) sealingly engaging the pipe 32 forsubstantially preventing the flow of fluid through the opening in thepipe 32 about the piston 236 in one preferred form. An extension 238 isconnected to the pipe 232 and the extension 238 is connected to a source240 of pressurized fluid or air or the like (power fluid), thepressurized power fluid from the source 240 being in fluidiccommunication with the opening in the pipe 32 via the extension 238.

During the installation of the control line 232, the leading end 234 ofthe control line 232 is connected to the piston 236. The piston 236,with the control line 232 attached thereto, is passed through thecontrol line feed assembly 230 and into the opening in the pipe 32. Thepiston 236 is passed through the opening in the pipe 32 to a positionbeyond the intersection of the extension 238 with the opening in thepipe 32. It should be noted that, depending upon the particularconstruction of the control line feed assembly, it may be necessary topass the control line 232 through the control line feed assembly 230,and then, connect the leading end 234 of the control line 232 to thepiston 236, the control line feed assembly 230 being connected to pipe32 in sealing engagement after the piston 236 has been inserted into theopening in the pipe 32. Various devices and arrangements of such devicescapable of functioning in the manner described before with respect tothe control line feed assembly 230 are known in the art.

After the piston 236 has been positioned within the opening in the pipe32 beyond the connection of the extension 238 to the pipe 32, powerfluid is passed from the source 240 through the extension 238 and intothe opening in the pipe 32. The power fluid fills the opening in thepipe 32, between the end thereof sealed via the control line feedassembly 230 and the piston 236, and the power fluid acts on the piston236 driving the piston 236 through the opening in the pipe 32 in thegeneral direction 242 (a direction generally parallel with the firstdirection 34) toward the second, remote installation (support structure12A), the piston 236 pulling the control line 232 through the opening inthe pipe 32 in the direction 242 via the connection between the piston236 and the control line 232.

The piston 236 is driven via the power fluid through the opening in thepipe 32 to the remote support structure 12A (shown in FIG. 8) and thepiston 236 is pulled or otherwise driven out from the opening in thepipe 32 at the remote support structure 12A, thereby disposing theleading end 234 of the control line 232 at the remote support structure12A. A stop (not shown) can be disposed in the opening through the pipe32 for stopping the movement of the piston 236 at a predeterminedlocation near the end of the pipe 32 at the remote support structure12A. After the movement of the piston 236 has been stopped, the piston236 then can be removed from the pipe 32. Assuming the control line 232is an electrical cable, for example, one end of the electrical cable isconnected to an electrical control means 244 located at the remotesupport structure 12A and the opposite end (or ends in the case of aplurality of conductors) of the electrical cable is connected to anelectrical power source or control apparatus (not shown) which may belocated either in the support structure 12 (FIG. 7) or at a vessel orinstallation (not shown) located near the surface 42 of the body ofwater, thereby establishing electrical continuity between suchelectrical power source (not shown) and the electrical control box 244.In any event, the present invention provides a convenient system forpassing control lines to remote locations.

In one other aspect, one or more removable stops (not shown) can bedisposed in the opening of the pipe 32 at predetermined locations alongthe length of the pipe 32. The movement of the piston 236 through thepipe 32 is stopped via each of the one or more stops (not shown). Thisfeature of the present invention is useful in installing various controllines, such as an electrical cable, for example, since the movement ofthe piston 236 is stopped at predetermined locations and, at each suchlocation, the length of the control line which has been fed into thepipe 32 can be compared with the length of conduit to the location of aparticular stop (not shown) for the purpose of determining if thecontrol line has become tangled or bunched or otherwise mis-installed insome portion of the pipe 32, since the length of the control line shouldbe the same as the known length of the pipe 32 to location of the stop(not shown) if the control line is properly installed within the pipe32.

Additionally, control lines such as a hydraulic type control line 232can be passed through the opening in the pipe 32 to the remote supportstructure 12A and connected to a reservoir for providing pressurizedfluid for control purposes at the remote support structure 12A in amanner exactly like that described before with respect to electricalcable type of control line 232. The hydraulic and the electrical controlline can be installed in the same pipe 32 or in different pipe (notshown) installed between the support structure 12 and the supportstructure 12A utilizing the pipe installation system 10 of the presentinvention. It will be understood, of course, that other members, such asa wire line, for example, can be installed within the pipe 32 in a likemanner for utilization in installing a second pipe within the pipe 32,as will be described below in connection with FIG. 9. A second pipe canbe installed in the pipe 38 utilizing a piston similar to the piston236, in a manner to be described in greater detail below in connectionwith FIG. 23.

One other preferred embodiment for providing a source of pressurizedfluid at a remote location (the remote support structure 12A) isdiagrammatically illustrated in FIG. 8. In this embodiment, theelectrical cable control line 232 is passed through a seal plug 246 andthe seal plug is installed in the opening in the pipe 32 at the remotesupport structure 12A, the seal plug 246 sealingly engaging the pipe 32and preventing the flow of fluid through the opening in the pipe 32about the seal plug 246. An accumulator 248 is located at the remotesupport structure 12A and the accumulator 248 is connected to theopening in pipe 32 via a conduit 250. The accumulator 248 is in fluidiccommunication with the source 240 via the conduit 250, the opening inthe pipe 32 and the extension 238 and the source 240 providespressurized fluid to the accumulator 248 for use at the remote supportstructure 12A. It should be noted that the pressurized fluid providedvia the pipe 32 can be connected directly to various apparatus locatedin the remote support structure 12A, thereby eliminating the need forthe accumulator 248, if desired in some applications, or the pressurizedfluid can be connected directly to some of the apparatus and accumulator248 can be utilized to supply other apparatus. Thus, in the embodimentshown in FIG. 8, the one pipe 32 provides a path extending between thesupport structure 12 and the remote support structure 12A foraccommodating the electrical cable and the pressurized fluid.

EMBODIMENT OF FIG. 9

The pipe installation system 10 of the present invention can be utilizedfor installing a second pipe 250 within the opening of the pipe 32. Inthis embodiment, the pipe 32 is installed in a manner like thatdescribed before, and the second pipe 250 is passed through the openingin pipe 32 and extended between the support structure 12 and another,remote support structure (such as the remote support structure 12A shownin FIG. 8) or some other remote installation, for example, the secondpipe 250 being installed through the opening in the pipe 32 utilizingthe pipe installation system 10 of the present invention in a mannerlike that described before with respect to the installation of the pipe32.

As shown in FIG. 9, the diameter formed via the outer peripheral surfaceof the second pipe 250 is smaller than the diameter formed via the innerperipheral surface of the pipe 32 to permit the insertion of the secondpipe 250 into and through the opening in the pipe 32.

The system illustrated in FIG. 9, can be utilized to replace worn orleaky pipe in certain situations, such as when well productivity isreduced to an extent that smaller flowline can accommodate the flowtherethrough, for example. In addition, the system illustrated in FIG.9, can be utilized to provide a steam jacketed type of flowline whereinsteam is passed within the opening of the pipe 32 and some other fluidis passed within the opening of the second pipe 250, the steam beingutilized to elevate the temperature level of the fluid flowing withinthe second pipe 250. In one other operational embodiment a corrosioninhibiting fluid can be passed through the opening in the pipe 32, whilesome other fluid is passed through the second pipe 250, the corrosioninhibiting fluid acting to protect the second pipe 250 which may beparticularly useful when installing pipe in corrosive environments.Moreover, if an electrical cable is run through the pipe 32 or throughthe second pipe 250 or in lieu of the second pipe 250, an electricallynon-conductive fluid may be passed through the pipe 32 in contact withsuch electrical cable for insulating such electrical cable andminimizing the possibilities of electrical failures (the non-conductivefluid also can be utilized as the power fluid provided to the remotesupport structure 12A), as described before with respect to FIGS. 7 and8. In yet another operational embodiment, the pipe 32 can be utilized toconvey fluid at one pressure level and the second pipe 250 can beutilized to convey fluid at some different pressure level.

EMBODIMENT OF FIG. 10

As mentioned before, a wire line can be attached to the leading end ofthe pipe 32 for pulling the pipe 32 from the support structure 12 tosome remote support structure or some other remote installation. Asshown in FIG. 10, a pipe plug 254 is connected to a leading end 256 ofthe pipe 32, such as by welding, for example, the pipe plug 254sealingly closing the opening through the pipe 32 at the leading end 256thereof.

One end of a wire line 258 is attached to the pipe plug 254 and theopposite end (not shown) of the wire line 258 is connected to a pullingmechanism, such as a winch, for example, for pulling the pipe 32 in amanner described before.

In one embodiment, as shown in FIG. 10, the wire line 258 comprises arelatively short first section 260 and a second section 262. One end ofthe first section 260 is connected to the pipe plug 254 and the oppositeend of the first section 260 is swivelingly connected to a swivel 264.One end of the second section 262 is swivelingly connected to the swivel264 and the opposite end of the second section 262 is connected topulling mechanism (not shown). The swivel 264 provides a means forswivelingly connecting the wire line 258 to the leading end 256 of thepipe 32, which permits rotational movement (twist) of the pipe 32relative to the wire line 258 and rotational movement (twist) of thewire line 258 relative to the pipe 32 during the installation of thepipe 32 without placing an undue stress on the connection between thewire line 258 and the pipe 32, thereby functioning to maintain thestructural integrity of the connection between the pipe 32 and the wireline 258 during the installation of pipe in accordance with the presentinvention.

In one embodiment, the blowin preventers 80, 82, 86, 92, 94 and 96 maybe eliminated. In this last-mentioned embodiment, the pipe 32 is passedthrough the riser 22 and through the forming assemblies 14 and 18 to aposition wherein the leading end of the pipe 32 is disposed generallyadjacent the flange 91 end of the conduit 88. In this position of thepipe 32, one end of the wire line 258 is passed through the conduit 88and connected to the leading end 234 of the pipe 32. A seal device (notshown) is disposed in the conduit 88 for maintaining the sealingintegrity of the space 66 as the wire line 258 is passed through theconduit 88 for connection to the pipe 32. After the wire line 258 isconnected to the pipe 32, the workmen move to the dry environmentprovided within the compartment 56 of the chamber 50. In this manner,the pipe 32 can be pulled through the conduit 88 and the spaces 60 and66 flooded with water since a relatively dry working environment isprovided within the chamber 50.

It should be noted that the wire line 258 could be connected to theleading end of the pipe 32 by divers operating in the water environmentoutside the space 66 while maintaining a relatively dry environmentwithin the space 66, in one operating mode. In the alternative, thespace 66 can be flooded with water and the wire line 258 can beconnected to the leading end of the pipe 32 by divers operating withinthe flooded environment within the space 66, thereby eliminating thenecessity of maintaining a dry environment within the space 66. If thespaces 60 and 66 or portions thereof are flooded during the pipe formingoperations, the spaces 60 and 66 could be sealed and the water thencould be pumped from the spaces 60 and 66 to provide the relatively dryenvironments for making the pipe terminal connections.

EMBODIMENT OF FIG. 11

Shown in FIG. 11 is a modified support structure 12C, which includes aplatform 52C connected to a wellhead 54C in a manner described beforewith respect to FIG. 1. A structure such as a rim 270 is connected tothe platform 52C and at least two guide posts 272 are connected to therim 270, each guide post 272 extending a distance from the rim 270terminating with an end 274.

The support structure 12C also includes a framework 276, having a firstend 278 and a second end 280. A first flange 282 is connected to thefirst end 278 and a second flange 284 is connected to the second end280, the first flange 282 being connectable to the second end 26 of theriser 22 and the second flange 284 being connectable to the flange 91C.It will be understood by those skilled in the art that various otherconnectors can be utilized in lieu of the flanges 91C, 282 and 284, theflanges 282 and 284 being shown in the drawings merely for the purposeof illustrating one embodiment of an acceptable connector.

One end of a guide arm 286 is connected to the framework 276 and theguide arm 286 extends a distance from the framework 276, a guide 288being connected to the guide arm 286, opposite the end connected to theframework 276. One end of a guide arm 290 is connected to the framework276 and the guide arm 290 extends a distance from the framework 276, aguide 292 is connected to the guide arm 290, opposite the end connectedto the framework 276. The guide 288 includes an opening (not shown) forreceiving a portion of one of the guide posts 272, generally near theend 274, and the guide 292 includes an opening (not shown) for receivinga portion of the other guide post 272, generally near the pointed end274.

The first forming assembly 14 is movably connected to the framework 276,generally near the first end 278, and the second forming assembly 18 ismovably connected to the framework 176, generally near the second end280. The first forming assembly 14 is positionable with respect to thesecond forming assembly 18 so that the forming assemblies 14 and 18cooperate to form the portions of the pipe 32 passing therethroughthrough predetermined angles, and each of the forming assemblies 14 and18 are positionable to form the portions of the pipe 32 passingtherethrough in predetermined radii, in a manner and for reasonsdescribed before.

During the operation, the framework 276, with the forming assemblies 14and 18 connected thereto, is lowered into the body of water to aposition wherein one of the guide posts 272 is inserted through theopening (not shown) in the guide 288 and the other guide post 272 isinserted through the opening (not shown) in the guide 292. The guideposts 272 are oriented on the platform 52C and the guides 288 and 290are oriented on the framework 276 to position the framework 276 on theplatform 52C in a predetermined operative position wherein the secondflange 284 is disposed near the flange 91C for connecting the framework276 to the platform 52C and wherein the first flange 282 is disposed forconnection to the second end 26 of the riser 22 to the first flange 282.After the framework 276 has been lowered into position, the secondflange 284 is connected to the flange 91C and the riser 22 is lowered toa position wherein the second end 26 of the riser 22 is disposedgenerally adjacent the first connector 282. The second end 26 of theriser 22 then is connected to the first connector 282, thereby securingthe riser 22 to the framework 276 in a predetermined operative position.In some applications, the riser 22 is connected to the first connector282 on the surface vessel (not shown) and the framework 276, with theriser 22 connected thereto, is lowered into position on the platform52C.

After the framework 276 has been connected to the platform 52C, the pipe32 is passed through the riser 22 and the first and the second formingassemblies 14 and 18, in a manner and for reasons described before.

After the pipe 32 (or pipes as the case may be) has been formed via theforming assemblies 14 and 18, the pipe 32 is severed via cutting means(not shown) or via a cutting mechanism associated with the blind ramblowin preventer 92, the cutting of the pipe 32 preferably beingeffected from a vessel or other structure (not shown) located near thesurface 42 of the body of water via remote controls (not shown) whichare connected to the cutting device (not shown) or the cutting mechanismassociated with the blowin preventer 92. After the pipe 32 (or pipes)has been severed, the portion of the pipe 32 in the framework 276 and inthe riser 22, the framework 276 and the riser 22 are removed from theplatform 52C, and then the chamber 50 is connected to the platform 52Cfor the purpose of providing a dry environment within which the variouspipe terminal connections can be effected. Alternately, divers can beutilized to make such terminal connections.

Since the forming assemblies 14 and 18 are supported on the framework276 within the body of water, the forming assemblies 14 and 18 can beconstructed to accommodate larger sizes of pipe as compared to theforming assemblies 14 and 18 shown in FIG. 1 which are supported withinthe spaces 60 and 66, the size of the last-mentioned forming assemblies14 and 18 being limited via the size of the spaces 60 and 66. Withrespect to the embodiment of the present invention shown in FIG. 11, thechamber 50 along with the auxiliary chamber 58 and the other auxiliarychambers can be connected to the platform 52C for the purpose ofproviding a dry environment within which the various pipe terminalconnections can be effected.

A tension member 106C can be connected at the connection 109C to theguide post 272 which is connected to the guide arm 290 so the tensionexerted by the tension member 106C at the connection 109C can beadjusted for the purpose of reducing the bending moments, in a mannerand for reasons described before in connection with the tension member106 shown in FIG. 1.

It should be noted that, in the embodiment of the invention shown inFIG. 11, the blowin preventers 78, 80, 82, 92, 94 and 96 are notincluded since the pipe installation system 10C is adapted for operatingin a wet environment.

It should be noted that various structures, devices and assemblies canbe utilized to position the framework 276 on the platform 52C and therim 270, the guide posts 272, the guide arms 286 and 290 and the guides288 and 292 have been described herein solely for the purpose ofillustrating one specific means for guidingly positioning the framework276 on the platform 52C.

EMBODIMENT OF FIGS. 12, 13 AND 14

As shown in FIGS. 12, 13 and 14, the forming assemblies 14 and 18 mayinclude a pair of shaping roller assemblies 300, in one embodiment, oneof the shaping roller assemblies 300 being disposed near the first end116 and the other shaping roller assembly 300 being disposed near thesecond end 118 of the frame assembly 110. The shaping roller assemblies300 each are constructed exactly alike and each includes a first pair ofshaping rollers 302 and 304 and a second pair of shaping rollers 306 and308. Each of the shaping rollers 302, 304, 306 and 308 is rotatinglysupported via means not shown in the drawings.

The shaping roller 302 is disposed about one hundred and eighty degrees(180°) from the shaping roller 304 with respect to the pipe 32, and theshaping roller 306 is disposed about one hundred and eighty degrees(180°) from the shaping roller 308 with respect to the pipe 32. Thefirst pair of shaping rollers 302 and 304 are spaced a distance axiallywith respect to the pipe 32 from the second pair of shaping rollers 306and 308.

Each of the shaping rollers 302, 304, 306 and 308 is constructed exactlyalike, and each shaping roller is generally circularly shaped, having anouter peripheral surface 310 and a recess 312 formed in the outerperipheral surface 310, as shown in FIG. 14. The outer peripheralsurface 310 of the shaping roller 302 and 304 may abut one another ormay be spaced apart, as shown in FIGS. 12, 13 and 14. The outerperipheral surface 310 of the shaping roller 306 is spaced a distancefrom the outer peripheral surface 310 of the shaping roller 308 forreceiving the pipe 32 passing therebetween. Each recess 312 is formed ona radius such that the portion of each shaping roller formed via therecess 312 engages a portion of the outer peripheral surface of the pipe32 and the shaping rollers are disposed about the pipe 32 such that theshaping rollers 302, 304, 306 and 308 cooperate to engage substantiallythe entire outer peripheral surface of the pipe 32 as the pipe 32 passesbetween the shaping rollers.

The shaping rollers 302, 304, 306 and 308 each are constructed of arigid material. The recesses 312 are shaped to engage the pipe 32 andcooperate to shape the portions of the pipe 32 passing between theshaping rollers in a shape having a generally circularly shapedcross-section. Thus, in the event the pipe 32 becomes deformed(non-circularly shaped cross-section) while passing through the formingassemblies 14 or 18 or in any other manner, the shaping rollerassemblies 300 function to re-shape the pipe 32 into a form having agenerally circularly shaped cross-section, before the pipe 32 is passedfrom the pipe installation system of the present invention.

EMBODIMENT OF FIG. 15

Shown in FIG. 15 is a modified pipe installation system 10H which isconstructed similar to the pipe installation system 10 shown in FIG. 1,except the pipe installation system 10H includes a modified supportstructure 12H adapted to support the first forming assembly 14 withinthe body of water, the second forming assembly 18 being supported withinthe relatively dry environment defined via the space 66H in a mannerlike that described before with respect to the second forming assembly18 shown in FIG. 1.

A conduit 300 extends through an opening 302 in the chamber 50H and theconduit 300 is sealingly secured to the chamber 50H in any convenientmanner, such as by welding, for example. One end of the conduit 300 isdisposed within the space 66H and an opening 304 extends through theconduit 300 providing communication between the space 66H and the waterenvironment outside the space 66H. A flange 306 is formed on the end ofthe conduit 300 which is disposed within the space 66H.

The blind ram blowin preventer 80 is connected to the flange 306, theram-type blowin preventer 82 is connected to the blowin preventer 80,and the annular blowin preventer 86 is connected to the blowin preventer82. The blowin preventers 80, 82 and 86 cooperate to maintain the space66H relatively dry while permitting a pipe to pass through the opening304 in the first and the second directions 34H and 36H and otherwiseoperate in a manner and for reasons described before with respect toFIGS. 1, 2 and 3.

The support structure 12H includes a modified framework 276H, which isconstructed similar to the framework 276 shown in FIG. 11, exceptbrackets 308 are formed on the second end 280H for connecting theframework 276H to the chamber 50H. The first forming assembly 14 ismovably connected to the framework 276H, generally near the first end278H in a manner like that described before with respect to FIG. 11. Inthis embodiment, the second forming assembly 18 is supported within thespace 66H, as mentioned before.

During the operation, the framework 276H, with the first formingassembly 14 connected thereto, is lowered into the body of water to aposition wherein the brackets 308 are oriented in a predetermineddisposition for connection to the chamber 50H, the brackets 308 beingconnected to the chamber 50H for connecting the framework 276H to thechamber 50H in a predetermined orientation with respect to the conduit300. After the framework 276H has been connected to the chamber 50H, theriser 22 is lowered into a position wherein the second end 26 of theriser 22 is disposed generally adjacent the first flange 282H. Thesecond end 26 of the riser 22 then is connected to the first flange282H, thereby securing the riser 22 to the framework 276H in apredetermined operative position. In some applications, the riser 22 isconnected to the framework 276H and the framework 276H, with the riser22 connected thereto, is lowered into position near the chamber 50H.

After the framework 276H has been connected to the chamber 50H, the pipe32 is passed in the first direction 34H through the riser 22, throughthe first forming assembly 14, through the opening 304 in the conduit300, through the blowin preventers 80, 82 and 86, through the secondforming assembly 18, through the blowin preventers 92, 94 and 96 andthrough the conduit 88. By the same token, the pipe 32 is passable inthe second direction 36H through the forming assemblies 14 and 18, thepipe 32 being passable in the first and the second directions 34H and36H through the forming assemblies 14 and 18 in a manner and for reasonsdescribed before.

By means (not shown) the framework 276H and other equipment such as thefirst forming assembly 14 can be encapsulated and sealingly connected tothe conduit 300. In this last-mentioned embodiment, the blowinpreventers 80, 82 and 86 may not be required. However, the blowinpreventers 80, 82, and 86 are useful for control in the event of leakseven in this type of structure.

EMBODIMENT OF FIG. 16

Shown in FIG. 16 is a modified pipe installation system 10J which isconstructed exactly like the pipe installation system shown in FIG. 1,except the pipe installation system 10J includes a modified supportstructure 12J adapted to support the first and the second formingassemblies 14 and 18 in the body of water, outside the relatively dryenvironment defined via the space 66J.

A conduit 310 extends through an opening 312 in the chamber 50J and theconduit 310 is sealingly secured to the chamber 50J in any convenientmanner, such as by welding, for example. One end of the conduit 310 isdisposed within the space 66J and an opening 314 extends through theconduit 310 providing communication between the water environmentoutside the space 66J, in a manner similar to that described before withrespect to the conduit 300 shown in FIG. 15. A flange 316 is formed onthe end of the conduit 310 which is disposed within the space 66J.

The blind ram blowin preventer 80 is connected to the flange 316, theram-type blowin preventer 82 is connected to the blowin preventer 80,and the annular blowin preventer 86 is connected to the blowin preventer82. The blowin preventers 80, 82 and 86 cooperate to maintain the space66J relatively dry while permitting a pipe to pass through the opening314 in the first and the second directions 34J and 36J and otherwiseoperate in a manner and for reasons described before with respect toFIGS. 1, 2 and 3.

One end of the conduit extension 318 is connected to the blowinpreventer 96 and the opposite end of the conduit extension 318 isconnected to the blowin preventer 86. The conduit extension 318 isdisposed within the space 66J and an opening 320 extends through theconduit extension 318 providing a passageway which is sized to permitthe passing of the pipe 32 therethrough in the first and the seconddirections 34J and 36J. The conduit extension 318 is removably andsealingly connected to the blowin preventers 86 and 96 to maintain theintegrity of the relatively dry environment of the space 66J during theoperation of the pipe installation system 10J. The conduit 318 permitsthe opening of the blowin preventers without flooding the space 66Jduring the installation of the pipe 32, thereby minimizing the wearingof the seal elements in the blowin preventers, as mentioned before.

The support structure 12J includes a framework 276J, which isconstructed exactly like the framework 276 shown in FIG. 11, except theflange 284J is removably connectable to a flange 322 formed on the endof the conduit 310, opposite the end of the conduit 310 which isdisposed within the space 66J. The first and the second formingassemblies 14 and 18 are each movably supported on the framework 276J ina manner that described before with respect to FIG. 11.

During the operation, the framework 276J, with the first and the secondforming assemblies 14 and 18 connected thereto, is lowered into the bodyof water to a position wherein the flange 284J is disposed near theflange 322, and the flange 284J is connected to the flange 322, therebysecuring the framework 276J to the chamber 50J. After the framework 276Jis connected to the chamber 50J, the riser 22 is connected to theframework 276J. The riser 22 can be connected to the framework 276Jprior to lowering the framework 276J into the body of water, if desiredin some applications.

After the framework 276J has been connected to the chamber 50J, the pipe32 is passed in the first direction 34J trough the riser 22, through thefirst and the second forming assemblies 14 and 18, through the conduit310, through the blowin preventers 80, 82 and 86, through the conduitextension 318 through the blowin preventers 92, 94 and 96 and throughthe conduit 88. By the same token, the pipe 32 is passable in the seconddirection 36J, through the first and the second forming assemblies 14and 18, the pipe being passable in the first and the second directions34J and 36J through the forming assemblies 14 and 18 in a manner and forreasons discussed before.

EMBODIMENT OF FIGS. 17, 18, 19 AND 20

Shown in FIGS. 17, 18, 19 and 20 is a modified pipe installationassembly 10K which is constructed similar to the pipe installationsystem 10J shown in FIG. 16, except the forming assemblies 14 and 18 aresupported on a modified support structure 12K. The modified supportstructure 12K includes a modified framework 226K and an offshoreplatform 400 or other offshore structure which is supported on the floor44 of the body of water, a portion of the platform 400 being disposed inthe body of water generally below the surface 42. The platform 400 is ofthe type commonly utilized with respect to various offshore operationsrelating to the drilling and production of oil and gas, for example, andgenerally comprises a plurality of support legs 402 which are anchoredin the floor 44 and a plurality of brace members 404 which are securedlyinterconnected to the support legs 402 (only two of the brace members404 being designated via a reference numeral in FIG. 17 and only threesupport legs 402 being shown in FIG. 17 for clarity). A portion of adeck 406 is secured to a portion of each of the support legs 402, andthe deck 406 is supported a distance above the surface 42 of the body ofwater via the support legs 402 and the interconnected brace members 404.The construction and utilization of various types of offshore platforms;such as the platform 400, are well known in the art and a detaileddescription is not required herein.

The framework 276K is removably connected to one of the support legs 402via a connector assembly 407, and, in general, the connector assembly407 is constructed such that the connector assembly 407 and theframework 276K are movably positionable on the support leg 402. Moreparticularly, the connector assembly 407 is slidably connected to one ofthe support legs 402 such that the connector assembly 407 and theframework 276K connected thereto are slidable in a first direction 408generally from the surface 42 toward the floor 44 of the body of waterand in a second direction 410 generally from the floor 44 toward thesurface 42 of the body of water.

It should be noted that, although the framework 276K is described hereinas being connected to one of the support legs 402 of an offshoreplatform 400, the framework 276K and the connector assembly 407 could beconnected to any support leg type of structure and the particularsupport leg structure associated with the platform 400 has been shown inFIGS. 17, 18, 19 and 20 merely for the purpose of illustrating oneembodiment.

The connector assembly 407 (shown more clearly in FIG. 18) includes: aconnector base 412, having a first end 414 and a second end 416; a firstconnector arm 418, having one end 420 which is connected to theconnector base 412 generally near the first end 414 thereof, and anopposite end 422 which is journally or otherwise movably connected tothe framework 276K generally near the first end 278K thereof; and asecond connector arm 424 having one end 426 which is connected to theconnector base 412 generally near the second end 416 thereof, and anopposite end 428 which is journally or otherwise movably connected tothe framework 276K generally near the second end 280K thereof. Thus, theframework 276K with the forming assemblies 14 and 18 connected theretois movable in a first direction 430 and in an opposite, second direction432 relative to the connector base 412 about the journal connectionbetween connector arms 418 and 424 and the framework 276K, for reasonsto be described in greater detail below.

As shown more clearly in FIG. 19, the connector base 412 has anarcuately shaped surface 434 extending between the first and the secondends 414 and 416 and forming a first and a second side 436 and 438. Theconnector base 412 is sized and shaped such that the first side 436engages one of the brace members 404 when the connector base 412 rotatesabout the support leg 402 in a first direction 440, thereby limiting themovement of the connector base 412 about the support leg 402 in thefirst direction 440. Also, the connector base 412 is sized and shapedsuch that the second side 438 engages one of the brace members 404 whenthe connector base 412 rotates about the support leg 402 in a seconddirection 442, thereby limiting the movement of the connector base 412about the support leg 402 in the second direction 442. Thus theengagement between the first and the second sides 436 and 438 and thebrace members 404 positions the connector assembly 407 and the framework276K connected thereto in a predetermined position relative to an axissubstantially corresponding to the axially extending centerline axis ofthe support leg 402.

In one embodiment, as shown in FIG. 19, a plurality of bearing members444 (only one of the bearing members 444 being designated via areference numeral in FIG. 19 for clarity) are interposed between thearcuately shaped surface 434 of the connector base 412 and an outersurface 446 of the support leg 402. The bearing members 444 bearinglyengage the connector base 412 and the support leg 402 to reduce thefriction therebetween as the connector assembly 407 is moved in thefirst and the second directions 408 and 410 along the support leg 402.

An opening 448 is formed through the first connector arm 418, as shownmore clearly in FIG. 19. As shown in FIGS. 18, 19 and 20, one end of ariser extension 450 is connected to the first flange 282K which issecured to the first end 278K of the framework 276K, and a portion ofthe riser extension 450 extends through the opening 448 in the firstconnector arm 418, the diameter formed via the outer peripheral surfaceof the riser extension 450 being less than the diameter of the opening448. A first bearing plate 452 is connected to the riser extension 450and the first bearing plate 452 extends a distance radially from theouter peripheral surface of the riser extension 450, thereby providing abearing surface 456 which bearingly engages a portion of a first surface458 of the first connector arm 418 generally near the opening 448. Asecond bearing plate 460 is connected to the riser extension and thesecond bearing plate 460 extends a distance radially from the outerperipheral surface of the riser extension 450, thereby providing abearing surface 462 which bearingly engages a portion of a secondsurface 464 of the first connector arm 418 generally near the opening448.

The second bearing plate 460 is spaced a distance from the first bearingplate 452 along an axis substantially corresponding to the axialcenterline axis of the riser extension 450, and a portion of the firstconnector arm 418 generally near the end 422 thereof is interposedbetween the first and the second bearing plates 452 and 460. The firstbearing plate 452 engages a portion of the first connector arm 418,thereby limiting the movement of the riser extension 450 through theopening 448 in the second direction 410. The second bearing plate 460engages a portion of the first connector arm 418, thereby limiting themovement of the riser extension 450 through the opening 448 in the firstdirection 408. Thus, the bearing plates 452 and 460 cooperate to securethe framework 276K to the first connector arm 418. It should be notedthat bearing members, similar to the bearing member 444, can beinterposed between the first connector arm 418 and the riser extension450, generally about the opening 448, or bearing members can beinterposed between the bearing surfaces 456 and 462 and the surfaces 458and 464 of the first connector arm 418 to reduce the friction betweenthe first connector arm 418 and the riser extension 450 when theframework 276K is rotated in the first and the second directions 430 and432 during the operation of the pipe installation system 10K.

A third bearing plate 466, having a bearing surface 468, is connected tothe second connector arm 424. As shown more clearly in FIGS. 18 and 20,the bearing surface 468 bearingly engages a portion of the framework276K, thereby limiting the movement of the framework 276K in the seconddirection 410, the bearing plates 452, 460 and 466 cooperating with theconnector arms 418 and 424 to support the framework 276K on theconnector base 412 in a manner such that the framework 276K is rotatablein the first and the second directions 430 and 432.

During the operation, the connector assembly 407 is connected to thesupport leg 402 and the framework 276K, with the forming assemblies 14and 18 connected thereto, is connected to the connector base 412 via theconnector arms 418 and 424. The unit comprising the connector assembly407, the framework 276K and the forming assemblies 14 and 18 is thenlowered in the first direction 408 via a cable 470, having one endconnected to the first end 414 of the connector base 412 and an oppositeend connected to a winch 472 located on the deck 406 of the platform400, as diagrammatically shown in FIG. 17. It should be noted that otherarrangements and devices can be utilized to raise and lower theconnector assembly 407 along the support leg 402 and the winch 472 andcable 470 have been shown and described herein merely for the purpose ofillustrating one embodiment.

The connector assembly 407 is lowered in the first direction 408 untilthe connector assembly 407 is located on the support leg 402 at adesired position. As shown in FIGS. 17 and 18, the riser 22K, moreparticularly, comprises a plurality of riser sections 474, 476, 478 and480 (four riser sections being shown in FIG. 17, for example). One endof the riser section 474 is connected to the second bearing plate 460and the opposite end of the riser section 474 is connected to one end ofthe riser section 476, the opposite end of the riser section 476 beingconnected to one end of the riser section 478 and the opposite end ofthe riser section 478 being connected to one end of the riser section480. It will be apparent from the foregoing that more or less risersections can be connected to form the riser 22K in a manner like thatjust described.

During the operation, the riser section 474 can be connected to thesecond bearing plate 460 and the connector assembly 407 then can belowered along the support leg 402 until the riser section 474 has beenlowered a sufficient distance to position the end thereof, opposite theend connected to the second bearing plate 460, in a predeterminedposition so the riser section 476 can be connected to the riser section474. Then, the connector assembly 407 is further lowered in the firstdirection 408 and the remaining riser sections 478 and 480 are eachconnected to form the riser 22K in a manner like that just describedwith respect to the connection of the riser sections 474 and 476.

After the riser 22K has been connected to the framework 276K and theunit comprising the riser 22K, the connector assembly 407 and theforming assemblies 14 and 18 has been positioned on the support leg 402in the desired positions, the rollers 124 (only some of the rollers 124being designated via a reference numeral for clarity) of the formingassemblies 14 and 18 are positioned to engage the pipe 32 passingtherethrough. Then, the pipe 32 is passed through the riser 22K andthrough the forming assemblies 14 and 18 for forming the pipe 32 in apredetermined radius through a predetermined angle in a manner describedin detail before.

The pipe 32 can be passed through the forming assemblies 14 and 18 inthe first and second directions 34K and 36K during the operation of thepipe installation system 10K, in a manner and for reasons describedbefore. In any event, assuming the pipe 32 has been passed through theforming assemblies 14 and 18 in the first direction 36K and it isdesired to disengage the pipe 32 from the forming assemblies 14 and 18,the rollers 124 of the forming assemblies 14 and 18 are each moved to apipe disengaging position, as diagrammatically shown in FIG. 20. Thedistance 184 (FIG. 6) is greater than the diameter formed via the outerperipheral surface of the pipe 32 and, in the pipe disengaging position,the rollers 124 of the first and the second forming assemblies 14 and 18are positioned such that the outer peripheral surface of the pipe 32 isspaced a distance from each of the rollers 124.

In the pipe disengaging position of the rollers 124, the framework 276Kwith the forming assemblies 14 and 18 connected thereto is rotated inthe first direction 430 and, since there is a clearance between the pipe32 and the rollers 124, the pipe 32 will remain in a relativelystationary position as the framework 276K and the forming assemblies 14and 18 are moved in the first direction 430 to a position (indicated indashed-lines in FIG. 19) wherein the pipe 32 is disengaged and removedfrom the forming assemblies 14 and 18. After the pipe 32 has beendisengaged from the forming assemblies 14 and 18, the pipe 32 is severedgenerally near the riser extension 450 and the portion of the pipe 32remaining in the riser 22K is withdrawn therefrom in the generaldirection 36K.

It should be noted that, in the embodiment of the invention shown inFIGS. 17, 18, 19 and 20, the forming assemblies 14 and 18 preferrablyinclude control units like the control unit 200, described before andshown in FIGS. 5 and 6, for positioning the rollers 124 in the pipeengaging position and the pipe disengaging position from some remotelocation, such as from the deck 406, for example.

The framework 276K can be rotated in the directions 430 and 432 viadivers or, in one other form, the framework 276K can be rotated in thedirections 430 and 432 from a remote location, such as from the deck406, for example. In this last mentioned embodiment, a driven gear (notshown) can be secured to the outer peripheral surface of the riserextension 450, and a drive gear (not shown) which is connected to anelectric or hydraulic motor (not shown) can be placed in gearingengagement with the driven gear (not shown) secured to the riserextension 450, the motor (not shown) being controlled from a remotelocation, such as the deck 406, for example. Thus, when the motor (notshown) is activated from the remote location, the drive gear (not shown)drivingly rotates the driven gear (not shown) and the riser extension450 connected thereto, thereby rotating the framework 276K. In thisembodiment, the motor (not shown) is reversible and thus the motor (notshown) can drivingly rotate the framework 276 in either the firstdirection 430 or the second direction 432 as controlled from the remotelocation.

In another embodiment, the third bearing plate 466 can be secured to theframework 276K (such as by welding, for example) and journally connectedto the second connector arm 424. In this embodiment, a driven gear (notshown) is secured to the third bearing plate 466 and a drive gear (notshown) which is driven via a reversible, remotely controlled electric orhydraulic motor (not shown), the motor (not shown) drivingly rotatingthe third bearing plate 466 and the framework 276K in the directions 430and 432 in a manner described before with respect to embodiment wherethe driven gear is connected to the riser extension 450.

In addition to the two embodiments described above, other apparatus forremotely rotating the framework 276K will be apparent to those skilledin the art in view of the foregoing, and the particular embodiments havebeen described above for the purpose of illustrating two operationalembodiments.

EMBODIMENT OF FIGS. 21 AND 22

Shown in FIGS. 21 and 22 is another modified pipe installation system10L which is constructed similar to the pipe installation system 10Kshown in FIGS. 17, 18, 19 and 20, except the forming assemblies 14 and18 are supported on a modified support structure 12L and the pipeinstallation system 10L includes a modified connector assembly 407K forslidably connecting the framework 276L to a support leg 402 in a mannersimilar to the connector assembly 407 shown in FIGs. 17, 18, 19 and 20and described before.

The connector assembly 407L includes a connector base 412L which isconstructed and connected to the support leg 402 in a manner exactlylike that described before with respect to the connector base 412 shownin FIGS. 17, 18, 19 and 20. The end 420L of a modified first connectorarm 418L is secured to the connector base 412L, generally near the firstend 414L, and the end 426L of a modified second connector arm 424L issecured to the connector base 412L, generally near the second end 416Land spaced a distance from the first connector arm 418L. Each of theconnector arms 418L and 424L extend a distance radially from connectorbase 412L. The end 422L of the first connector arm 418L, opposite theend 420L which is connected to the connector base 412L, is secured tothe frame assembly 110 of the first forming assembly 14, and the end428L of the second connector arm 424L, opposite the end 426L which isconnected to the connector base 412L, is pivotally connected to theframework 276L.

The framework 276L comprises: a first hydraulic cylinder 500, having acylinder base 502 and a cylinder rod 504; a second hydraulic 506, havinga cylinder base 508 and a cylinder rod 510; and a third hydrauliccylinder 512, having a cylinder base 514 and a cylinder rod 516. Thehydraulic cylinders 500, 506 and 512 comprise what is sometimes referredto herein as a framework control assembly 518, and the framework controlassembly 518 cooperates to positionably support the forming assemblies14 and 18 on the connector base 412L such that the forming assemblies 14and 18 are movably positionable relative to each other so the formingassemblies 14 and 18 can be positioned in various positions for formingthe pipe 32 passing therethrough through predetermined radii and so theforming assemblies 14 and 18 can be positioned in one position whereinthe pipe passageways 16 and 20 are substantially aligned for removingthe pipe 32 in a manner to be described in greater detail below.

The cylinder rod 504 is movably disposed in one end of the cylinder base502 such that the cylinder rod 504 is movable in one direction 520wherein the cylinder rod 504 is extended a distance from the cylinderbase 502 in one actuated condition of the first hydraulic cylinder 500and the cylinder rod 504 is movable in one other direction 522 whereinthe cylinder rod 504 is retracted a distance into the cylinder base 502in one other actuated condition of the first hydraulic cylinder 500. Theend of the cylinder base 502, opposite the end having the cylinder rod504 movably disposed therein, is pivotally connected to the frameassembly 110 of the first forming assembly 14, and the end of thecylinder rod 504, opposite the end of the cylinder rod 504 movablydisposed in the cylinder base 502, is pivotally connected to the frameassembly 110 of the second forming assembly 18.

The cylinder rod 510 is movably disposed in one end of the cylinder base508 such that the cylinder rod 510 is movable in one direction 524wherein the cylinder rod 510 is extended a distance from the cylinderbase 508 in one actuated condition of the second hydraulic cylinder 506and the cylinder rod 510 is movable in one other direction 526 whereinthe cylinder rod 510 is retracted a distance into the cylinder base 508in one other actuated condition of the second hydraulic cylinder 506.The end of the cylinder base 508, opposite the end having the cylinderrod 510 movably disposed therein, is pivotally connected to the frameassembly 110 of the first forming assembly 14, and the end of thecylinder rod 510, opposite the end of the cylinder rod 510 movablydisposed in the cylinder base 508, is pivotally connected to the frameassembly 110 of the second forming assembly 18.

The cylinder rod 516 is movably disposed in one end of the cylinder base514 such that the cylinder rod 516 is movable in one direction 528wherein the cylinder rod 516 is extended a distance from the cylinderbase 514 in one actuated condition of the third hydraulic cylinder 512and the cylinder rod 516 is movable in one other direction 530 whereinthe cylinder rod 516 is retracted into the cylinder base 514 in oneother actuated condition of the third hydraulic cylinder 512. The end ofthe cylinder base 514, opposite the end having the cylinder rod 516movably disposed therein, is pivotally connected to the end 428L of thesecond connector arm 424L, opposite the end 426L which is connected tothe connector base 412L, and the end of the cylinder rod 516, oppositethe end of the cylinder rod 516 movably disposed in the cylinder base514, is pivotally connected to the frame assembly 110 of the secondforming assembly 18. More particularly, the cylinder rod 516 ispivotally connected to the support frame 120 of the second formingassembly 18 at the same pivot connection as the cylinder rod 516 of thesecond hydraulic cylinder 506.

In one embodiment, control lines (not shown) are connected to thehydraulic cylinders 500, 506 and 512 and the control lines (not shown)are connected to a control unit (not shown) which is located at someremote location, such as on the deck 406 of the offshore platform 400(FIG. 17), for example. In this manner, the actuated condition of thehydraulic cylinders 500, 506 and 512 is controllable from the remotelocation for positioning the forming assemblies 14 and 18 inpredetermined positions relative to each other to form the pipe 32passing therethrough through predetermined radii and for positioning theforming assemblies 14 and 18 in a position such that the pipepassageways 14 and 18 are substantially aligned. Control lines andcontrol units for remotely controlling the actuated condition ofhydraulic cylinders are well known in the art and a further detaileddescription of the construction and the operation of such control linesand control units is not required herein.

It should be noted that, in the embodiment of the invention shown inFIGS. 21 and 22, the first forming assembly 14 is secured in a fixedposition relative to the connector base 412 and the framework controlassembly 518, more particularly, movably positions the second formingassembly 18 in predetermined positions relative to the first formingassembly 14.

During the operation, the framework 276L is connected to the connectorassembly 407L, and the connector assembly 407L along with the framework276L is lowered in the first direction 408 along the support leg 402 ina manner described before in connection with the embodiment shown inFIGS. 17, 18, 19 and 20, thereby lowering the forming assemblies 14 and18 which are connected to the framework 276L. In one form, the frameworkcontrol assembly 518 is conditioned such that the second formingassembly 18 is moved into a position wherein the pipe passageway 20through the second forming assembly 18 is substantially aligned with thepipe passageway 16 through the first forming assembly 14 (shown in FIG.22), thereby positioning the first and the second forming assemblies 14and 18 generally near the connector base 412L as the connector assembly407L is lowered along the support leg 402.

After the connector assembly 407L with the framework 276L connectedthereto has been positioned on the support leg 402, the frameworkcontrol assembly 518 is actuated or conditioned to move the secondforming assembly 18 to some predetermined position relative to the firstforming assembly 14, such as the position shown in FIG. 21, for example.More particularly, the framework control assembly 518 conditions thesecond hydraulic cylinder 506 such that the cylinder rod 510 is moved inthe direction 526 generally away or out from the cylinder base 508, andthe third hydraulic cylinder 512 is conditioned such that the cylinderrod 516 is moved in the direction 530 generally away or out from thecylinder base 514, the first hydraulic cylinder 500 being conditioned toretain the cylinder rod 504 in a position wherein the cylinder rod 504remains retracted within the cylinder base 502. In this condition of theframework control assembly 518, the second forming assembly 18 is movedin a direction generally away from the connector base 412 and in adirection 410 to a position wherein the second forming assembly 18 ispositioned relative to the first forming assembly 14 in somepredetermined position, such as the position shown in FIG. 21, forexample, for forming the pipe 32 passing through the forming assemblies14 and 18 through a predetermined radius.

To position the second forming assembly 18 in the position shown in FIG.21, the first hydraulic cylinder 500 is not actuated and the cylinderrod 504 remains retracted within the cylinder base 508 as the frameworkcontrol assembly 518 positions the second forming assembly 18. Assumingthe first hydraulic cylinder 500 is conditioned such that the cylinderrod 504 is moved in the direction 520 generally away or out from thecylinder base 502 and the second and the third hydraulic cylinders 506and 512 are conditioned such that the cylinder rods 510 and 516 remainin a stationary position relative to the cylinder bases 508 and 514, thecylinder rod 504 of the first hydraulic cylinder 500 moves the secondforming assembly 18 in a general direction 520 causing the secondforming assembly 18 to be pivotally rotated about the pivot connectionbetween the cylinder rods 510 and 516 and the second forming assembly18, thereby causing the angular position of the second forming assembly18 relative to the first forming assembly 14 to be changed. It will beapparent to those skilled in the art from the foregoing that the angularposition of the second forming assembly 18 relative to the first formingassembly 14 can be selectively changed by changing the distance one ormore of the cylinder rods 504, 510 and 516 is moved into or out from therespective cylinder bases 502, 508 and 514, thereby selectively changingthe radius through which the pipe 32 is formed as the pipe 32 is passedthrough the forming assemblies 14 and 18.

When it is desired to pull the framework 276L in the second direction410 along the support leg 402, the framework control assembly 518 isactuated such that the hydraulic cylinders 500, 506 and 512 are eachconditioned to cause the cylinder rods 504, 510 and 516 to be retractedtoward the respective cylinder bases 502, 508 and 514 until the secondforming assembly 18 has been moved to a position wherein the pipepassageways 16 and 20 substantially are aligned, as shown in FIG. 22. Asthe second forming assembly 18 is moved to the position shown in FIG. 22wherein the pipe passageways 16 and 20 substantially are aligned, theportion of the pipe 32 extending between the first and the secondforming assemblies 14 and 18 is straightened to some extent.

After the pipe passageways 16 and 20 have been aligned, the rollers 124of the first and the second forming assemblies 14 and 18 are positionedto engage and straighten the pipe 32 as the pipe 32 is passedtherethrough in the second direction 36L. Thus, the first and the secondforming assemblies 14 and 18 cooperate to straighten the pipe 32 as thepipe 32 is withdrawn or passed through the forming assemblies 14 and 18so the pipe 32 can be passed in the general direction 36L through therelatively straight riser 22L. In this manner, the pipe 32 can bewithdrawn in the second direction 36L through the forming assemblies 14and 18 and through the riser 22L without first cutting the previouslyformed portions of the pipe 32 from the remaining relatively straightportions of the pipe 32, although it should be noted that it may bedesirable to cut the pipe 32 generally near the second forming assembly18, before removing the remaining portion of the pipe 32 in someapplications.

In some applications it may be desirable to leave the straight portionof the pipe 32 and the formed portion of the pipe 32 as an integral unitafter the forming operation. In this manner, the straight portion of thepipe 32 extends along the support leg 402 in the first direction 34L toa position generally near the deck 406 for connection to other apparatusand the straight portion of the pipe 32 extends along the support leg402 in the second direction 36L to a position wherein the formed portionof the pipe 32 causes the pipe 32 to change direction and extendoutwardly or generally perpendicularly from the support leg 402. In thisapplication, the second forming assembly 18 is moved to the positionwherein the pipe passageways 16 and 20 substantially are aligned in amanner described before, and then the connector assembly 407L with theframework 276L connected thereto is moved in the second direction 410 toa position wherein the forming assemblies 14 and 18 is removed from thepipe 32, the forming assemblies 14 and 18 essentially being pulled overthe pipe 32 as the connector assembly 407L is moved in the seconddirection 410. Assuming the riser 22L is constructed of riser sectionssimilar to the riser 22K described before in connection with theembodiment shown in FIGS. 17, 18, 19 and 20, each riser section can beremoved after the connector assembly 407L has been moved in the seconddirection 410 a sufficient distance so the riser section is clear of thepipe 32 and positioned in a position where the riser section can bedisconnected from the riser 22L. After all of the riser sections havebeen removed in a manner just described, the connector assembly 407Lthen is moved in the second direction 410 to a position wherein the pipe32 has been cleared from the forming assemblies 14 and 18, therebydisconnecting the forming assemblies 14 and 18 from the pipe 32 whileleaving the pipe 32 in a position wherein a portion of the pipe 32extends generally along the support leg 402 and another portion of thepipe 32 extends in a direction generally angularly from the support leg402 (the exact angle depending on the angle through which the pipe 32 isformed as the pipe 32 passes through the forming assemblies 14 and 18).

EMBODIMENT OF FIG. 23

Shown in FIG. 23 is a portion of modified pipe installation system 10Mwhich is utilized to install a second pipe 540 through the pipe 32. Inthis embodiment, a piston 542 is connected to a leading end 544 of thesecond pipe 540, and one end of the pipe 32 is connected to a pipe feedassembly 546 which seals the end of the pipe 32 connected thereto, whileallowing the second pipe 540 to be passed in sealing engagementtherethrough into and through the opening in the pipe 32. The piston 542is sized to be inserted into and slidingly moved through the opening inthe pipe 32, the piston 542 including portions (not shown) sealinglyengaging the pipe 32 for substantially preventing the flow of fluidthrough the opening in the pipe 32 about the piston 542 in a mannersimilar to that described before in connection with the embodiment shownin FIGS. 21 and 22. A source 548 of pressurized power fluid or air orthe like (power fluid) is connected to the pipe 32 downstream from thesecond forming assembly 18 (not shown in FIG. 23), the pressurized powerfluid being in fluidic communication with the opening in the pipe 32 viaan extension 550.

During the installation of the second pipe 540, the leading end 544 isconnected to the piston 542 and the piston 542, with the second pipe 540connected thereto, is passed through the pipe feed assembly 546 and intothe opening in the pipe 32. Power fluid then is passed from the source548 into the opening in the pipe 32 and the power fluid fills the spacebetween the outer peripheral surface of the second pipe 540 and theinner peripheral surface of the pipe 32, the power fluid acting on thepiston 542 and driving the piston 542 through the opening in the pipe 32in a general direction 552. As the piston 542 is driven in the direction552 the second pipe 540 is pulled through the pipe 32 via the connectionbetween the second pipe 540 and the piston 542, thereby installing thesecond pipe 250 in the opening of the pipe 32.

It should be noted that, although the various embodiments of the pipeinstallation system of the present invention have been described hereinas including a first and a second forming assembly 14 and 18, theforming assemblies 14 and 18 cooperate to support the rollers 124 inpredetermined positions for engaging the portions of the pipe 32 passingtherethrough and forming the pipe 32 in predetermined radii and throughpredetermined forming angles. Thus, it is not necessary to support therollers 124 on separate forming assemblies and the present inventioncontemplates pipe forming systems wherein the rollers 124 are supportedon a single forming assembly or systems wherein the rollers 124 aresupported on more than two forming assemblies. In addition to theforegoing, the present invention contemplates pipe installation systemswhere more or less than six rollers 124 are supported on a formingassembly. For example, either one or two rollers 124 could be supportedon a support frame 120 and a number of support frames 120 could besupported on a framework such that the various support frames 120support the rollers 124 in positions for engaging and forming the pipe32 in predetermined radii and through predetermined forming angles.

The methods and apparatus of the present invention are useful forinstalling various members, such as wire lines, cables, control lines,conductors, conduits and the like, for example, and the "pipe 32" andthe various references in this specification and in the claims to suchpipe shall not be construed to limit the present invention as defined inthe claims to installing any particular type of member.

Changes may be made in the construction and the operation of the variouscomponents and assemblies described herein and in the various steps andin the sequence of steps of the methods described herein withoutdeparting from the spirit and the scope of the invention as defined inthe following claims.

What is claimed is:
 1. A method for installing a pipe between a supportstructure and a remote second support structure beneath the surface of abody of water, the method comprising the steps of:passing the pipethrough at least one forming assembly disposed in the support structureand forming portions of the pipe in a predetermined radius with each ofthe forming assemblies; forming a portion of the pipe with one of theforming assemblies on a radius to provide at least one curved section inthe pipe; passing the pipe between the support structure and the remotesecond support structure; and positioning the curved section in the pipebetween the support structure and the remote second support structure.2. A method for installing a pipe between a support structure and aremote second support structure beneath the surface of a body of water,the method comprising the steps of:passing the pipe through at least oneforming assembly disposed in the support structure and forming portionsof the pipe in a predetermined radius with each of the formingassemblies; passing the pipe between the support structure and theremote second support structure; connecting a pipe between the supportstructure and the remote second support structure; passing a flexiblemember through the pipe and between the support structure and the remotesecond support structure; and connecting the flexible member between thesupport structure and the remote second support structure.
 3. The methodof claim 2 defined further to include the steps of:passing a fluidthrough the pipe between the support structure and the remote secondsupport structure; and passing another fluid through the flexible memberbetween the support structure and the remote second support structure.4. The method of claim 3 wherein the flexible member is an electricalcable or the like and wherein the method is defined further to includethe step of:passing a fluid through the space between the pipe and theflexible member and between the support structure and the remote secondsupport structure.